The 50 most-cited articles in Applied Mechanics and Materials, 2017

Natural fiber composites are presently replacing the synthetic fiber in many fields. The present research work study is an attempt to manufacture and test the sisal/banana fiber reinforced polymer composites. Composite have been manufactured using banana and sisal fiber along with epoxy resin as reinforcement. With these composites drilling has been carried out to study the factors and combination of factors that influence the delamination of drilled unidirectional sisal-banana fiber reinforced composites. Drilling experiments were performed based on the L9-Taguchi method. Delamination factor evaluated for the selected parameters spindle speed, feed and diameter of the drill tool with the help of signal to noise ratio, ANOVA analysis and to obtain the conditions for minimum delamination.

We present a methodology to analyze and visualize an ensemble of finite pointset method (FPM) simulations that model the viscous fingering process of salt solutions inside water. In course of the simulations the solutions form structures with increased salt concentration value, called viscous fingers. These structures are of primary interest to domain scientists since it is not deterministic when and where viscous fingers appear and how they evolve. To explore the aleatoric uncertainty embedded in the simulations we analyze an ensemble of simulation runs which differ due to stochastic effects. To detect and track the viscous fingers we derive a voxel volume for each simulation where fingers are identified as subvolumes that satisfy geometrical and topological constraints. Properties and the evolution of fingers are illustrated through tracking graphs that visualize when fingers form, dissolve, merge, and split. We provide multiple linked views to compare, browse, and analyze the ensemble in real-time.

A new meta-heuristic gravitational search(GS) algorithm is proposed for simultaneous scheduling of machines, and two identical automated guided vehicles(AGVs) in a flexible manufacturing system(FMS). It minimize the makespan and completes the assigned jobs faster with possible savings of the resources. The adequacy of the algorithm is demonstrated by solving several problems and comparing with existing results.

In this publication we report on our progress in investigating the energy efficient production of rare earth permanent magnets by Laser Beam Melting in the powder bed (LBM). This innovative additive manufacturing process offers the potential to produce magnets of complex geometries without an energy intensive oven sintering step. Another advantage that increases the efficiency of this possible new process route is the high degree of material utilization due to a near net shape production of the magnets. Hence only little material is wasted during a post processing machining step. The main challenge in processing rare earth magnet alloys by means of LBM is the brittle mechanical behavior of the material and the change in microstructure due to the complete remelting of the magnet powder. We therefor expanded the parameter study presented in previous work in order to further increase relative density and magnetic properties of the specimens. In this context process stability and reproducibility could also be increased. This was achieved by investigating the impact of different exposure…

The wiring system is one of the most important and one of the most expensive part of modern passenger vehicles. It ́s production is done manually to nearly 100% since the early years of car manufacturing. Until today it wasn ́t possible to automatize these cost-intensive step of the car production in an effective and cost efficient way. This paper shows how the routing process of the wiring harness as a part of the whole production process can be automatized with easy and cost efficient production methods. Collaborative robots and 3D-printed prototypes of cable grippers were used to treat with the complexity of the job and to finally create a sustainable and cost efficient production system. Further the routing concept has been brought to a prototypical production cell which has been tested in various routing experiments at the institute’s laboratory. Finally, a discussion of the results brings up the strengths and weaknesses of the concept and shows possible solutions.

The residue of Ethylene-Vinyl Acetate (EVA) generated in the footwear industry is an economic and environmental problem as it requires large area for storage in landfills and is not biodegradable or capable of transformation into other polymers. Its use as a lightweight aggregate in mortar and concrete results in a material with lower density but with reduced strength. In this paper, piassava fibers (Attalea funifera Martius) were used as reinforcement of lightweight concrete containing 4% and 6% of EVA, with the goal of improving the flexural strength of the material. The determination of density, compressive strength and flexural strength were performed at 28 days of age. The experimental results demonstrate that the addition of EVA decreases the density and flexural strength of the concrete in proportion to the amount of addition, but a recovery resistance is obtained when the piassava fibers are added in amounts of 1 to 2% by volume.

In order to improve the driving safety of vehicles, a non-pneumatic safety tire named mechanical elastic wheel was developed, and the structural components of mechanical elastic wheel and the method of determining the rubber material parameters of Mooney-Rivlin model were introduced. Uniaxial tensile tests of the rubber in different parts of mechanical elastic wheel were carried out with a stretch test machine and the material parameters and of the Mooney-Rivlin model were determined by fitting the experimental data. Finite element method (FEM) was used to validate the stability of the fitted data. The results show that the obtained material parameters have high accuracy and can be a reference for the subsequent finite element simulation of mechanical elastic wheel.

Production of A6063/SiC composite with various weight fractions (3%, 6%, 9%) were prepared by using permanent mould casting was investigated. The preferred mean particle size of SiC is 60 μm. In addition, A6063 alloys were cast for comparison purposes. The alloys and composites were given a T6 heat treatment process (solution treatment at 520 °C, water quenching at room temperature and artificial ageing at 180 °C), Also Microstructure, hardness and tensile properties of these composites were evaluated and compared. In addition, tribological properties of these composites were evaluated using a Pin-on-Disc apparatus with various parameters (constant load of 10N and varying velocities as follows 0.5m/s, 1m/s, 1.5m/s, 2m/s) .The microstructure of the composites shows homogenous distribution of SiC particles in the Al matrix except in the A6063/9% SiC composite. The wear and mechanical properties of composites improve with increasing the weight fraction of SiC Wear morphology studies show that higher wear rate in case of unreinforced specimen compared to heat treated composites. Whereas…

The three drivers of environmental change: climate change, population growth and economic growth, result in a range of pressures on our coastal environment. Coastal development for industry and farming are a major pressure on terrestrial and environmental quality. In their process most of industry using sea water as cooling water. When water used as a coolant is returned to the natural environment at a higher temperature, the change in temperature decreases oxygen supply and affects marine ecosystem. This research is presents results from ongoing study on application of Landsat 8 for monitoring the intensity and distribution area of sea surface temperature changed by the heated effluent discharge from the power plant on Paiton coast, Probolinggo, East Java province. Remote sensing technology using a thermal band in Operational Land Imager (OLI) sensor of Landsat 8 sattelite imagery (band 10 and band 11) are used to determine the intensity and distribution of temperature changes. Estimation of sea surface temperature (SST) using remote sensing technology is applied to provide ease of…

In this investigation, A357 (Al-7.5%Si-0.5%Mg) alloy/Al2O3 composites with various weight fractions (4%, 8%, 10%) were prepared by using permanent mould casting. In addition, A357 alloys were cast for comparison purposes. Microstructure, hardness and tensile properties of these composites were evaluated and compared with as-cast alloy. In addition, tribological properties of these composites were evaluated using a Pin-on-Disc apparatus at a constant sliding velocity of 1m/s and pressure of 0.35 MPa. The microstructure of the composites shows homogenous distribution of Al2O3 plate-like particles in the Al matrix except in the A357/10%Al2O3 composite. The wear and mechanical properties of composites improve with increasing the weight percentage of Al2O3 upto 8% and then decreases. Particularly, mechanical properties of the A357/10%Al2O3 composite are lower than the alloy indicating that the critical weight fraction of Al2O3 reinforcement in the A357 alloy is 8%. Wear morphology studies show that higher wear rate in case of unreinforced specimen was associated with higher thickness of…

Surface finish plays a critical role in functional performance of machined components. This study investigates machining finish of Ti-6Al-4V alloy prepared by Additive Manufacturing (AM) with a series of slot-milling experiments. The study compares the machined AMed part with that made of the conventional wrought Ti-6Al-4V. The microstructure of AMed parts is acicular α and Widmanstatten α lath structures compared to lamellar α structure of that in the wrought parts. Due to the unique microstructure from AM process, the AMed parts present higher strength and lower ductility. Therefore, a lower surface roughness is obtained in the milling of AMed parts compared to its counterpart of wrought parts. In addition, the machined surface of AMed parts possesses a topography of discontinued ridges. It is believed that the topography is due to low ductility of AMed part. The results show that the machined AMed part presents better surface finish. The study provides a guidance to optimization of machining parameters for AMed Ti-6Al-4V alloys.

Physical phenomena in a nanometric machining process were studied by molecular dynamics simulations. A cylindrical tool was indented and then moved laterally on an initially flat workpiece. The focus of the study is on the effect of lubrication on the nanoscale. Therefore, the indentation and the scratching were studied both in vacuum and submersed in a lubricant. All materials were modeled by Lennard-Jones truncated and shifted potential sites. It is observed, that in the lubricated case, a substantial part of the cutting edge of the tool is in dry contact with the workpiece. Nevertheless, compared to the dry scenario, the lubrication lowers the coefficient of friction. However, the work which is needed for the indentation and the scratching is not reduced. The processed surface is found to be smoother in the lubricated case. As expected, the lubrication has an important influence on the temperature field observed in the simulation.

The demand for lightweight structures made of sandwich panels is ever increasing in many Industrial sectors. Numerous research efforts have been taken by various researchers in this area in terms of weight and cost reduction. Sandwich panel is a composite structure and it is an excellent alternative material in place of weight reduction without sacrificing its strength and stiffness characteristics. The geometrical characteristics of honeycomb core sandwich panels as well as their physical and mechanical properties such as compressive strength, flexural stiffness, core shear moduli, shear strength and stiffness are analyzed. The sandwich panels are available in various shapes and sizes to the service requirement. The commercially available sandwich panels have different core materials such as foams, FRPs and metallic and non metallic materials. The structure of the core typically varies as truss type and honeycomb. The face sheets and the core materials are bonded using thermo-set resins.

The aim is to study the mechanical property and dry sliding wear behaviour of Al7068/graphite composite with various weight fractions (5%, 10%, 15%) were prepared by liquid metallurgy route was investigated. The average particle size of graphite is 40 μm. In addition, Al7068 alloys were cast for comparison purposes. The alloys and composites were given a T6 heat treatment process (solution treatment at 540 oC, water quenching at room temperature and artificial ageing at 170 oC) .Microstructure, hardness and tensile properties of these composites were evaluated and compared with as-cast alloy and the composites without T6 heat treatment. In addition, tribological properties of these composites were evaluated using a Pin-on-Disc apparatus with different parameters (constant velocity of 2m/s and varying loads as follows 10N, 15N, 20N, 25N, 30N) .The microstructure of the composites shows homogenous distribution of graphite particles in the Al matrix except in the Al7068/15% graphite composite. The wear and mechanical properties of composites improve with increasing the weight fraction…

In this article, an attempt was made to study the mechanical behaviour of AA7068 - 6 vol. % of MoS2 - X vol. % of WC (X = 0, 5, 10 and 15) hybrid aluminium composites produced by blend–press–sinter methodology. Compacted Powders (700MPa) were sintered at different temperatures (450 0c, 500 0c and 550 0c ) in order to find the influence of sintering temperature on mechanical properties and tribological behavior of AA7068 hybrid composites.The sintered samples have been characterized by x-ray diffraction (XRD) method for identification of phases and also to investigate the phase changes. The change in density, hardness and porosity values of composites were reported. The composite with 15 vol. % of tungsten carbide and 6 vol. % of MoS2 showed the highest hardness and density at the sintering temperature range of 550 0c. Pin-on-disc type apparatus was used for determining the wear loss occurring at different conditions. The hybridization of the two reinforcements enhanced the wear resistance of the composites, especially under high applied load, sliding distance and sliding speeds. Due…

Facing the energy crisis and environmental problems, saving energy of construction machinery, especially in the hydraulic excavator is very important. Regeneration of the potential energy is an effective solution to save energy. However, the conventional hybrid excavator can’t regenerate the potential energy. This paper proposes a new structure of boom system of hydraulic excavator as well as a control strategy. The focus of the paper is using hydraulic transformer to regenerate energy and reusing the regenerated energy. The simulation is carried out by the AMESim software. From the simulation results, this new system has a high efficiency for energy saving.

The development and expansion of tourism region is a complex phenomenon and it is necessary to be studied interdisciplinary. Nowadays, the development of tourism region in Baluran National Park increases rapidly. In this case, the growth and expansion of tourism region has a close relation with sustainability, tourist growth restrictions, and carrying capacity, three aspects must be concerned in managing tourism. The purpose of this research is to manage the sustainability of coastal tourism using carrying capacity concept. Based on the results, there are four coastal tourism activities which suitable in Baluran National Park, there are, beach tourism, snorkelling, diving, and mangrove excursion. Beach tourism in the recreation category with a total area of 92 ha can hold up to 9200 tourists/day, diving area up to 189 ha can hold up to 1512 tourists/day, snorkelling area up to 101 ha can hold up to 673 tourists/day and mangrove excursion with an area of 272 ha can hold up to10880 tourists/day. Thus, the total tourists per day for the coastal tourism is 22.265 person.

Many experimental and numerical works have been done on different configurations of solar stills to optimize the design by investigative the effect of climatic, operational and design parameters on its performance. One of the most important of the operational parameters that has received a considerable attention in the literature is the brine depth. A study was subsequently conducted to verify this trend by an experimental investigation on three types of solar still that was fabricated with an area of 1 m2 and tested in the composite climate of Coimbatore, Tamilnadu, India, (Latitude: 11°N; Longitude; 77°E and an altitude of 409 m above sea level) with five different brine depths, namely 1, 4, 6, 8 and 10 cm. The present study clearly validated that the decreasing trend in productivity with the increase of brine depth.

A preliminary assessment of the available wave energy around Indonesia is presented. The computations have been conducted by using the wave data collected during 35 years period from 1980 to 2014 from European Centre for Medium-Range Weather Forecasts (ECMWF). Location situated in the south of Java Sea has the most promising location for wave power potential, with the highest energy resource available in the month of January to December. The yearly mean wave power is maximum at the Java sea can reach 22 kW/m.

The present study is undertaken to investigate the influence of annealing and normalizing heat treatment on the bimetallic interface microstructures of 304 stainless steel and gray cast iron. The current work is aim to control the bimetal interface microstructures by different types of heat treatment processes to improve performance of the bimetallic castings performance. For low temperature annealing, specimens are heated to 760 0C for 60 min in an electrical heating furnace. For high temperature annealing and normalizing, specimens are heated to 920 0C for 120 and 240 min. A different interface structures are obained for all heat treated samples. Annealing and normalizing induce a significant effect on the diffusion of C and Cr elements and slightly effect on the diffusion of Ni element. Thickness of interface layer 1 (austenite + carbide) increases by increasingthe annealing temperature.

The Electron Beam Melted (EBM) method is one of the attractive attention thing additive manufacturing methods. By using an EBM additive manufacturing method, CP Ti and Ti-6Al-4V specimen were fabricated with a certain processing parameters. The mechanical properties such as fatigue limit, tensile properties including microstructural characteristics of CP Ti and Ti-6Al-4V specimens fabricated by EBM were confirmed and were compared with the conventional Ti alloys. Additive manufacturing was obtained high strength by creating martensite due to rapid cooling. On the other hand, void occurrence cannot be avoided by the method of using powder, accordingly it had a low fatigue strength value. Therefore, this study focused on that the values of fatigue characteristics of the EBM specimens and conventional specimens were compared and analyzed. EBM CP Ti had good mechanical properties such as yield strength, ultimate tensile strength, elongation and fatigue limits, approximately as same as casting CP Ti. EBM Ti-6Al-4V showed good mechanical properties, but fatigue limits were lower than…

Within this couple of years, a group of skilled people called “Maker” are interested in building everything by themselves. They attempt to develop a small manufacturing environment where allows people to execute a low cost fabrication task. In order to achieve this goal, they utilized flexible and smart manufacturing machines like 3D printers, laser cutter and small CNC. Especially 3D printer, its excellent performances had grasped many government administrators’ attention and developing 3D printing industry has become an important policy of many countries. Some of 3D printing patents have been expired within recent years. This event makes opens sources of 3D printers grow very fast. The Kossel Mini, Rostock and Prusa i3 are the typical examples. All of development kits of the above printers can be freely obtained from the Internet. This event makes a low cost fabrication become possible. However, the quality of their printed parts is dependent on a series of calibrations. The calibrations include defining the dimensions of hard frame of the printer, configuring firmware and setting…

Multilayer cutting is widely used in finish machining process of thin-walled parts to improve the machining precision. The paper presents a cutting allowance optimization method using genetic algorithm to improve the machining quality and efficiency of thin-walled parts in the field of aerospace. Considering the coupling relationship of the deformation between the layers in layered milling, the parameterized finite element model of thin-walled parts in side milling process is established. The best relationship between the workpiece stiffness and the cutting force is determined though iterative calculations, and the deformation caused by the cutting force can be minimized. The results show that the optimized distribution of the depth of finishing cutting was better than the experience. The method proposed in this paper can reduce the deformation of the workpiece during the machining process, and thus improve the machining accuracy.

Hydroxyapatite was synthesized using calcium originated from waste eggshell that was reacted with phosphate obtained from diammonium hydrogen orthophosphate by ball milling technique. The samples were mixed at different time from 5 to 150 min. The structure, function group and morphology of hydroxyapatite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM). The result showed that the hydroxyapatite phase was appeared after ball milling about 5 min and confirmed with FTIR results. The FE-SEM of hydroxyapatite powder was spherical shape and agglomerate. The crystallinity of hydroxyapatite was increased with increasing ball milling time. This experiment showed that the nano hydroxyapatite could synthesized from waste eggshell by ball milling technique.

The purpose of this paper is to present the main aspects and results of an experimental study to determine the bond strength between the concrete of a column of an existing structure (old concrete) and the concrete that will be used in its strengthening project (new concrete). For the bond strength tests, a specimen was conceived, called Double Sleeve specimen. The bond strength results obtained from the tests using Double Sleeve specimens, called Double Sleeve Tests, were compared to the results obtained from using the Slant Shear Test. The values for the bond strength between the two concretes, obtained from the Double Sleeve Tests, were either below or above the values obtained from linear regression of the Slant Shear Test results, depending on the sleeve diameter and the ratio of transverse reinforcement used. This fact, enabled concludes that the Double Sleeve Test is the most appropriate test to evaluate the bond strength between concretes of columns strengthened.

This article focuses on the effect of iron (Fe) addition on the fabrication of Ti-alloys. Fe is a potential inexpensive element that can be added to Ti-alloys to reduce their cost. This metal can also be used to replace expensive β-stabilizing alloying elements, such as vanadium (V) and molybdenum (Mo), for Ti-alloys. Fe has also been utilized as a novel cost-effective alloying element to decrease Ti-alloy costs and to design other alloys, such as Ti metal 62S (Ti-6Al-1.7Fe-0.1Si) and Ti-Fe-O-N Ti-alloy. This technical perspective has been further applied to fabricate new Ti-alloys. For example, Ti8LC and Ti-5.5Al-1Fe with good mechanical features have been developed as novel Ti-alloys in China and Japan, respectively. Nowadays, vanadium (V) of Ti-6Al-4V alloy is completely replaced with Fe to produce Ti-Al-Fe alloy series. Three new alloys, namely, Ti-6Al-xFe, where x = 1, 2, and 3 wt%, are introduced to examine the effect of Fe addition on the microstructure and mechanical properties of Ti-alloys.

The working environment of the inspection robot is a high altitude flexible cable environment. The robot navigating process must be stable and reliable. The robot mechanism grips the line though locomotion mechanism when navigating obstacles. The locomotion mechanism needs to have a strong clamping capacity and stability. According to the environmental characteristics of transmission lines, a novel locomotion mechanism of inspection robot is presented. The locomotion mechanism adopting differential mechanism can grip different diameter lines. The Tri-Step reducer design to ensure that the various model lines of rapid firmly clamped. The locomotion mechanism is introduced, and the gripper force is analyzed. The experiment results demonstrate that the mechanism has such characteristics as strong grip ability, good motion stability, and different diameter lines gripping capability.

Codeine (3-methylmorphine) is an opiate that is widely used to treat mild or moderate pain and cough suppression. It is the second predominant alkaloid in opium with a mild sedative effect. In the present study, we describe an electrochemical sensor for codeine detection by using the DNA aptamers against codeine. In the sensing protocol, a dually-labeled DNA aptamer probe was designed to be labeled at one end with HS, and at its another end with dabcyl as an electrochemical tag to produce electrochemical signal via recognization occurrence. One special electrochemical marker was prepared by modifying ZnS nanoparticle with-cyclodextrins (ab. ZnS-CDs), which employed as electrochemical signal provider and would conjunct with the codeine probe modified electrode through the host–guest recognition of CDs to dabcyl. With codeine adding, aptamer folding allows the ZnS-CDs into soultion that caused an increase of current signal. This sensor has the ability to detect 37pM codeine. Our study demonstrates that the biosensor has good specificity and stability. It can be used to detect codeine.

For decades, multiple lighting simulation software packages and plugins for commercial software have been developed in an effort to ease the usage and integration of simulation into the lighting design process. In this effort, one of the main challenges is to provide lighting designers with an easy and comprehensive access to simulation results. Visualization is used as a means to achieve this goal. In this paper, we explore two of the most used free lighting simulation packages towards the identification of visualization techniques that facilitate the access to the simulation results as well as the identification of opportunities for the enhancement of simulation-assisted lighting design processes. A test case of a metal workshop illustrates the output produced by both software packages. Based on this exploration, we identified an open gap regarding three main aspects: interactive exploration of simulation results, visualization of compliance with lighting standards, and visual comparison of lighting solutions. We provide a discussion on how approaches from other domains can be…

To improve the simulation accuracy of the thermal characteristic of ball screw feed drive systems, a dynamic thermal-structure coupling model, which considered the effect of the thermal contact conductance (TCC) of the solid joint on the accuracy of simulation results, was proposed to conduct thermal characteristic analysis of ball screw feed drive systems. The predictive model for TCC was proposed based on the micro morphology description of rough surfaces and the contact load distribution of solid joints. Then, the dynamic thermal-structure model of the ball screw feed drive system was established. To validate the effectiveness of the dynamic thermal-structure coupling model, thermal characteristic experiments of the ball screw feed drive system were conducted under different feed rates. The results showed that the simulation accuracy of temperature field and axial thermal elongation can be improved from 65% to 87% and from 70% to 85%, respectively.

Various sizes SiO2 colloidal particles in the size range of 260-950 nm were synthesized by the stöber method by adjusting the amount of ammonia from 9.0 ml to 3.0 ml while keeping 20.0 ml tetraethyl orthosilicate (TEOS), 125.0 ml ethanol, 6.0 ml ammonia and 18.0 ml distilled water fixed. In addition, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the crystallinity and morphology of the synthesized SiO2 colloidal particles; the XRD result show that the SiO2 colloidal particles are amorphous at room temperature; the SEM results demonstrated that the amount of ammonia could have significant effects on the size, size distribution and sphericity of the SiO2 colloidal particles. SiO2 colloidal particles were resulted with good monodispersity when the amount of ammonia was in the range of 6.0-90 ml, while SiO2 colloidal particles with double size distribution were obtained when the range is 3.0-4.5 ml; on the other hand, SiO2 spheres were resulted with good sphericity when the ammonia is in the range of 6.0-7.5 ml.

Carbonous material always promotes the development of human being’s civilization. The diamond-like carbon (DLC) is one of the new kinds of materials. In the past fifty years, DLC has reached the level of semi-industrialization. From the unintentional discovery of DLC to the booming study all over the world, and then to the wide use in various fields, DLC has become a symbol of the era. In order to study the relationship between the structure and properties of DLC, researchers have been working on its classification and puting forward its theoretical model. Preparation technologies of DLC have been improving continuously. Nowadays there are some popular technologies such as the unbalanced magnetron sputtering technology, the electron cyclotron resonance radio frequency technology, the femtosecond laser technology, and the meshed plasma immersion ion deposition technology. The application field of DLC has expanded from simple life products to the field of machinery precision cutting tools, precision molds, medical devices and implants, and the aerospace field. Although DLC has…

In this paper, an embedded facial recognition system whose platform consists of pcDuono-V2 board with ARM-processor inside and a Linux-kernel-based operating system, Ubuntu, is implemented. A camera is set up on the platform to take human face images. A facial recognition program consisting of AdaBoost algorithm, Haar-like features, integral image method, and cascade classifiers is utilized to recognize images. The AdaBoost algorithm is a modified Boosting algorithm, which is a machine learning algorithm for training cascade stronger classifiers based on Haar-like features, where Haar-like features are the foundation of the recognition. An integral image method is used to speed up the calculation of corresponding rectangle feature values for Haar-like features. The whole facial recognition comprises facial training procedures and recognition procedures. In facial training procedures, sufficient amounts of positive and negative picture samples are necessary for getting Haar-like features to the recognition system. AdaBoost algorithm is then used to the system for training cascade…

Natural fibers have been used to reinforce materials in many composite structures. Many types of natural fibers have been investigated including flax, hemp, ramie, sisal, abaca, banana etc., due to the advantage that they are light weight, renewable resources and have marketing appeal. These agricultural wastes can also be used to prepare fiber reinforced polymer hybrid composites in various combinations for commercial use. Application of composite materials in structural applications has presented the need for the engineering analysis. The present work focuses on the fabrication of polymer matrix composites by using natural fibers like banana and cotton which are abundant in nature and analysing the effect of mechanical properties of the composites on different surface treatments on the fabric. The effect of various surface treatments (NaOH, SLS, KMnO4) on the mechanical properties namely tensile, flexural and impact was analyzed and are discussed in this project. Analysing the material characteristics of the compression moulded composites; their results were measured on sections…

Due to the rapid depletion of conventional energy resources like fossil fuels and their harmful effects on the environment, there is an urgent need to seek alternative and sustainable energy sources. Wind energy is considered as one of the efficient source of energy which can be converted to useful form of energy like electrical energy. Though the field of wind engineering has developed in the recent era there is still scope for improvement in the effective utilization of energy. Energy efficiency in wind turbine is largely determined by the aerodynamics of the turbine blades and the characteristics of the turbulent fluid flow. The objective of this paper is to have a review on the improvement of Horizontal Axis Wind Turbine (HAWT) blade design by incorporating biomimetics into blades. Biomimetics is the field of science in which we adapt designs from nature to solve modern problems. The morphology of the wing-like flipper of the humpback whale (Megaptera novaeangliae) has potential for aerodynamic applications. Instead of straight leading edges like that of conventional hydrofoils,…

The antibacterial property of several types of transition metals such as silver, nickel, zinc, and copper substituted hydroxyapatite (HA) composite coatings was investigated against staphylococcus aureus (S. aureus). Microstructural characterization and phase analysis of feedstock powders and as-deposited coatings were carried out using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). Transition metals-substituted hydroxyapatite/PEEK coatings were successfully deposited using cold spraying parameters of 10-14 bars at preheated air temperature between 150 and 160 °C. The results indicated that copper substituted hydroxyapatite showed the best antimicrobial property against S. aureus.

In this study, we evaluated warmth retention ability of polyurethane foam (non-laminated and laminated) plying with fabrics. The warmth retention ratio, measured by KES-F7, was used for expressing the thermal property of plied samples. Experimental results revealed that the warmth retention ratio of samples that were plied with fabrics were higher than the foams in plain (i.e. without plying with fabric). For non-laminated foams, the fabrics had generally increased the warmth retention ratio by 10%. For laminated foams, the increase was about 4 to 5% in the warm retention ratio. By comparing the warmth retention ratio between the non-laminated foams and laminated foams, laminated foams have higher heat retention power. Being a close-to-skin garment, the air permeability is an important factor to determine their usage. Thus, we examined the air permeability of the different samples and the results were discussed properly.

Products features have a significant effect on consumers’ buying intention as it identifies which of the consumers’ needs be fulfilled. In addition, emotional brand benefit is one of the important factors to switch consumers from actual consumption to eco-friendly purchasing. In this study, we explored the relationship between brand green image, environmental performance and consumer green consciousness and purchase intention by survey with target group age ranged 18-28. The survey results indicated that there is a direct relationship between brand green image environmental performance and consumer green consciousness and purchase intention of fashion products.

Radiation shielding properties of rubber containing barite (BaSO4) at different concentration were evaluated by using beam transmission method for 59.5 keV energy of 241Am radioactive sources. The linear attenuation coefficients of these materials have been measured using gamma spectrometer which contains NaI(Tl) detector. It was found that the linear attenuation coefficient increase with the increase of barite content up to a value of 25% (in weight). The linear attenuation coefficients were 0.050, 0.086, 0.110, 0.129 and 0.138 mm-1 and the HVL were 13.9, 8.1, 6.3, 5.4 and 5.0 mm for the barite concentration of 5%, 10%, 15%, 20% and 25% by weight, respectively. The X-ray shielding ability was confirmed by using radiographic technique.

The lightweight design of aluminum automobile wheel can easily bring about all kinds of defects during die-casting, which often causes wheel frame deformation and creep damages in the future use and in turn affects traffic safety. To understand the evolution of mold flow, temperature field, and solidification, the low pressure die-casting processes of A356 aluminum wheel were simulated by Anycasting software package. Various casting parameters combined with the designs of flow channel and overflows were adopted to reduce the defects occurred in wheel products. In addition, we adopted the retained melt modulus (RMM) to predict the position of defects to be formed as well as their distribution so as to eliminate the shrinkage voids and porosity defects during die-casting. The research findings showed that the setting up of overflow tank could effectively prevent the formation of shrinkage void and porosity of die-castings and significantly promote the quality and productivity of die-casting wheel products.

The efflux velocity equation from Torricelli is well known in fluid mechanics. It can be derived analytically applying Bernoulli’s equation. Bernoulli’s equation is obtained integrating the momentum equation on a stream line. For verification purposes the efflux velocity for a large tank or vessel was also computed analytically applying the momentum equation, delivering, however, a different result as the Torricelli equation. In order to validate these theoretical results the vertical and the horizontal efflux velocity case was simulated with computational fluid dynamics CFD. Furthermore, simple experiments for the horizontal and vertical efflux equation were performed.

Quartz glass is a typical hard and brittle material. During the manufacturing process of quartz glass components, ultra-precision grinding is widely used due to its high throughput and good dimensional accuracies. However, grinding will unavoidably induce large surface and subsurface damage. In this study, the surface and subsurface damage characteristics of quartz glass substrates ground by diamond wheels with different grit sizes were investigated in terms of surface roughness, surface topography, subsurface microcrack characteristic, and subsurface damage depth. Discussion was also provided to explore corresponding reasons of surface and subsurface damage induced by diamond grinding wheels with different grit sizes of #1500 and #2000. The experiment results showed that the surface roughness, surface damage, and subsurface damage depth induced by #2000 quartz glass was ground by #1500 diamond grinding wheel, and in ductile mode when ground by #2000 diamond grinding wheel.

This paper aims to provide an assembly method to improve mechanical assembly quality. In order to improve the variation propagation control in rotationally symmetric cylindrical components assembly, the eccentric and tilt errors of a single rotor stage were taken into account using a connective assembly model and the eccentric deviation in a mechanical assembly was minimized by properly selecting component orientations. Compared to the minimum cumulative error, the maximum cumulative error was reduced by 71 percent, and the average cumulative error was reduced by 57 percent in the assembly of three components. This article provides an assembly method through variation propagation control in rotationally symmetric cylindrical components assembly. The method could be extended to rotationally symmetric cylindrical components assembly, for example in the assembly of aero-engine components.

On the macrolevel metal matrix composites (MMCs) resemble a homogeneous material. However, on the microlevel they have an inhomogeneous microstructure. This paper will show how heterogeneities affect the effective macroscopic properties the material, i.e. the effective properties. This investigation is done using computational homogenization techniques. Finite element (FE) simulations were conducted in ABAQUS in combination with MATLAB, using material parameters for aluminum alloy AA2124 and silicon carbide SiC to develop a representative volume element (RVE) of the MMC AMC217xe.

We compare the performance of three interatomic interaction potentials for describing the evolution of plasticity and phase transformations in Si: the well established Stillinger-Weber potential, a recent modification used in the description of Al/Si composites, and a modification of the well known Tersoff potential. We show that the generation of dislocations and the evolution of plasticity are well described by the Stillinger-Weber potential and its modification, while the phase transformation to the high-pressure bct5 modification and the subsequent amorphization are better included in the modified Tersoff potential.

Manufacturing companies have to implement engineering changes in manufacturing systems to remain competitive in changing conditions. Physical influences like collisions or load capacities have to be considered for a proper planning of these changes by modeling and simulating the influences. To consider these physical influences, a concept is presented for the integration of physical model into realization of engineering changes. The concept provides information for the feasibility of the work steps for the execution and enables an efficient planning. Hence, planning mistakes can be detected before changes are executed and the negative impact on ongoing manufacturing can be avoided.

The angle-resolved scattered light sensor OS500 (made by Optosurf in Ettlingen, Germany) is an optical measuring device that is becoming more and more frequently used inindustrial applications and for the characterization of surfaces in general as well as for measuringroughness and shape. The angle-resolved measurement principle allows the statistical distributionof the gradients of a surface, resulting from the reflectance of the light at the flank angles of theareas examined, to be measured and consequently enables the geometric surface texture to beevaluated. Thus the topography of surfaces is not measured; instead the gradients are evaluated.Since the scattered light sensor measures angles and not distances, the sensor is immune to out-ofplanevibrations in the direction of measurement. Another distinct characteristic of the scattered light sensor is the high degree of sensor dynamics, which when combined with the statisticalanalysis of the surface angles, allows even the finest changes in the surface structure to be detected. Accordingly, it makes sense to use the sensor to…

Considering the complexity of workflow in distribution center and the ability of simulation for analysis and optimization of such systems, the application of simulation technology in distribution center is researched in this paper. Taking the distribution center of J mall for example, the third distribution mode of the mall is studied, which procures goods from many suppliers and stores in its own warehouse, then delivers them to the customers according to the different orders. Through the analysis of the Flexsim simulation software, the problems existing in the distribution center are found. And according to the analysis, the improvement suggestions are given and verified by simulation. By comparing the simulation results, it can be concluded that the waiting wastes in receiving area, temporary storage and dispatch area are decreased, and the average utilization rates of the stations become more appropriate. Finally, the output quantities of dispatch area are increased and the efficiency of distribution center is improved.

In recent years, sustainability and environmental effect of concrete became the main concern. Substituting cement with the other cementitious material without decreasing mechanical properties of a mixture could save energy, reduce greenhouse effect due to mining, calcination and limestone refining. Therefore, some industrial by-products such as fly ash, silica fume, and Ground Iron Blast Furnace Slag (GIBFS) would be used in this study to substitute cement and aggregate. This substitution would be applied on the porous concrete mixture to minimize the environmental effect. Slag performance will be optimized by trying out variations of fly ash, silica fume, and slag as cement substitution material in mortar mixture. The result is narrowed into two types of substitution. First, reviewed from the fly ash substitution effect on binder material, highest compressive strength 16.2 MPa was obtained from mixture composition 6% fly ash, 3% silica fume and 17% grinding granular blast-furnace slag. Second, reviewed from slag types as cement substitution and silica fume substitution, highest…

The importance of environmental consequences due to diverse substances that are emitted during the production of concrete is recognized, but environmental performance tends to be evaluated separately from the economic performance and durability performance of concrete. In order to evaluate concrete from the perspective of sustainable development, evaluation technologies are required for comprehensive assessment of environmental performance, economic performance, and durability performance based on a concept of sustainable development called the triple bottom line (TBL). Herein an assessment method for concrete eco-efficiency is developed as a technique to ensure the manufacture of highly durable and eco-friendly concrete, while minimizing both the load on the ecological environment and manufacturing costs. The assessment method is based on environmental impact, manufacturing costs, and the service life of concrete.