Actual Wear Research Articles

Studies on wear resistance of PTFE filled with glass and bronze particles based on Taguchi technique

An attempt has been made to study the influence of wear parameters like applied load, sliding speed, sliding distance on the dry sliding wear of polytetrafluroethylene (PTFE), PTFE + 25% glass and PTFE + 40% bronze composites. Experiments, based on the techniques of Taguchi, were performed to acquire data in a controlled way. An orthogonal array and the analysis of variance were employed to investigate the influence of process parameters on the wear of composites. The worn surfaces were examined using scanning electron microscope (SEM). The experimental results show that sliding distance and applied load were found to be the more significant factors among the other control factors on wear. The objective is to establish a correlation between dry sliding wear of composites and wear parameters. These correlations were obtained by multiple regressions. A good agreement between the predicted and actual wear resistance was seen.

Tool Engage Investigation in Nickel Superalloy Turning Operations

This paper reports the results of an experimental study of the tool wear and cutting forces in turning of Inconel 718 with coated carbide inserts. Inconel 718 is a difficult-to-cut nickel-based super-alloy commonly used in aerospace industry. The effects of cutting speed, feed rate and cutting tool geometry on tool wear have been widely analyzed in literature. Turning operations on complex components such as aircraft engines casings require the insert replacement at the end of each geometric feature manufacturing, independently from the actual tool wear level. For this reason, it is important to preserve tool integrity mainly in the most critical phase of operation (i.e., when the tool engages the workpiece). In fact, if the tool is damaged in this stage the quality of the whole operation is compromised. The attention has been focused on engage cutting conditions because the phenomenon that appears in this critical step plays a wide influence on tool integrity and, consequently, on the quality of the operation. For this purpose a nickel-based super alloy ring-workpiece, (Inconel 718), has been machined in lubricated cutting conditions by using a CNC lathe with carbide coated tools. Two variables have been investigated in this study: the Depth Of Cut (DOC) and the approaching Engage angle (En). In the studied working conditions Speed (S), Feed-rate (F) and removed volume (Vrim) were kept constant. Both tool wear and cutting forces evolution during cutting have been analyzed.

Analytical Study on Wear Interaction between Rail-Wheel

The interaction between wheel-rail produced defects on each other. Many studies of wear were done using pin-on-disc tribometer on interaction between the wheels – rail. The present paper proposes analytical study on wear. Wear rates were determined using depth of wear prediction on the interaction surfaces between wheel-rail. This prediction has been validated using pin-on-disc experimental technique using normal load of 100 N. The results show that the predictive equation developed can be used to predict the actual wear rate.

Simulation of Vitrified CBN Grinding Wheel Abrasive Wear Based on SPH

This paper used spatial random cutting plane method for modeling the real irregular grain shapes, and method of smoothed particle hydrodynamic (SPH) was used to establish CBN grinding wheel abrasive wear model. In order to research the wear mechanism of CBN abrasive and the relationships between grinding parameters and grinding wheel wear, simulation of the wheel abrasive wear process was simulated by the LS-DYNA explicit dynamics. According to the results obtained by simulation of abrasive wear model which has the same law with the actual wear abrasive, it is has realistic instructive significance to the actual grinding process of vitrified CBN grinding wheel.

Heat stress in chemical protective clothing: porosity and vapour resistance

Heat strain in chemical protective clothing is an important factor in industrial and military practice. Various improvements to the clothing to alleviate strain while maintaining protection have been attempted. More recently, selectively permeable membranes have been introduced to improve protection, but questions are raised regarding their effect on heat strain. In this paper the use of selectively permeable membranes with low vapour resistance was compared to textile-based outer layers with similar ensemble vapour resistance. For textile-based outer layers, the effect of increasing air permeability was investigated. When comparing ensembles with a textile vs. a membrane outer layer that have similar heat and vapour resistances measured for the sum of fabric samples, a higher heat strain is observed in the membrane ensemble, as in actual wear, and the air permeability of the textile version improves ventilation and allows better cooling by sweat evaporation. For garments with identical thickness and static dry heat resistance, but differing levels of air permeability, a strong correlation of microclimate ventilation due to wind and movement with air permeability was observed. This was reflected in lower values of core and skin temperatures and heart rate for garments with higher air permeability. For heart rate and core temperature the two lowest and the two highest air permeabilities formed two distinct groups, but they did not differ within these groups. Based on protection requirements, it is concluded that air permeability increases can reduce heat strain levels allowing optimisation of chemical protective clothing. Statement of Relevance: In this study on chemical, biological, radiological and nuclear (CBRN) protective clothing, heat strain is shown to be significantly higher with selectively permeable membranes compared to air permeable ensembles. Optimisation of CBRN personal protective equipment needs to balance sufficient protection with reduced heat strain. Using selectively permeable membranes may optimise protection but requires thorough consideration of the wearer's heat strain.

Feasibility of utilizing response surface methodology for predicting wear of steels

In this study, statistical models were developed in terms of contact load, sliding time, hardness, and r/min using the response surface method (RSM). In RSM, central composite design (CCD) was selected for wear tests. In wear tests, responses are the measurements of the weight loss from specimens. Specimens were machined from AISI 4140 and AISI 1040 steels. The wear model was estimated by the least-squares method for each steel after conducting tests in terms of CCD. When they were analysed, the agreement between the predicted and actual wear resistance values was observed within −8 per cent. Then, model adequacy tests were made by performing several new wear tests. Moreover, the models were applied to new tests which consist of different materials and wear factors for the feasibility. In conclusion, predictive wear models using RSM can be applicable for a certain wear system in order to estimate its wear rate.

Abrasive Wear Behavior of Granite-Filled Glass-Epoxy Composites by SiC Particles Using Statistical Analysis

This experimental investigation deals with the evaluation of abrasive wear behavior of Glass Epoxy (G-E) composites on pin-on-disc test rig. A plan of experiments, based on the Taguchi Design of Experiments, was performed to acquire data in controlled way. An orthogonal array and the analysis of variance were employed to investigate the percentage of contribution of various process parameters like sliding speed, applied load, sliding distance and their interactions affecting the abrasive wear volume loss of composites. The correlations between the various factors affecting the abrasive wear behavior of composites were obtained by using multiple linear regression equations. The obtained results indicate that applied load and sliding distance were the wear factors that have the highest physical as well as statistical influence on the abrasive wear behavior of both filled and unfilled G-E composites. A good agreement between the predicted and actual wear resistance was observed within ± 12%.

Study on Wear-Preventing of Needle Valve in Fuel Injection System Mounted on DME Engine

The purpose of this paper is to provide theoretical support for the structural design to prevent the wear of needle. The actual wear of the orientation part of the needle in scrapped needles was researched. The presented results showed that the main reason to the wear of the orientation part of needle was the dynamic instability and the abrasives enter into the surface of orientation part which increases the wear, and that the calculation model of dynamic stability was proposed to prevent the wear of needle. This model was a pressure rod, one end of which was fixed, the other was free, and the two ends were pressed on axial force which changes with time. Besides, the classic formula of dynamic stability of pressure rod was changed rationally, so as to correspond with the calculation model. It will play a part in preventing the wear of needle.

Validation of Accelerometer Wear and Nonwear Time Classification Algorithm

the use of movement monitors (accelerometers) for measuring physical activity (PA) in intervention and population-based studies is becoming a standard methodology for the objective measurement of sedentary and active behaviors and for the validation of subjective PA self-reports. A vital step in PA measurement is the classification of daily time into accelerometer wear and nonwear intervals using its recordings (counts) and an accelerometer-specific algorithm. the purpose of this study was to validate and improve a commonly used algorithm for classifying accelerometer wear and nonwear time intervals using objective movement data obtained in the whole-room indirect calorimeter. we conducted a validation study of a wear or nonwear automatic algorithm using data obtained from 49 adults and 76 youth wearing accelerometers during a strictly monitored 24-h stay in a room calorimeter. The accelerometer wear and nonwear time classified by the algorithm was compared with actual wearing time. Potential improvements to the algorithm were examined using the minimum classification error as an optimization target. the recommended elements in the new algorithm are as follows: 1) zero-count threshold during a nonwear time interval, 2) 90-min time window for consecutive zero or nonzero counts, and 3) allowance of 2-min interval of nonzero counts with the upstream or downstream 30-min consecutive zero-count window for detection of artifactual movements. Compared with the true wearing status, improvements to the algorithm decreased nonwear time misclassification during the waking and the 24-h periods (all P values < 0.001). the accelerometer wear or nonwear time algorithm improvements may lead to more accurate estimation of time spent in sedentary and active behaviors.

Radical Fashion and Radical Fashion Innovation

This is a study of the related concepts of radical fashion and radical fashion innovation. Radical fashions are defined here as those that may never enter the market at all, and exist primarily on runway shows, in exhibitions and in publicity; by contrast, radical fashion innovations may be very successful in the marketplace. Radical fashions represent a clear break from the old designs, as opposed to incremental fashions, which are defined as an extension or evolution of the old designs. Using this definition, radical fashion seems to be at odds with the definition of marketable fashion. Nevertheless, while most radical fashions do not enter the market at all and live only in runway shows, exhibitions, and museums, there are many examples of radical fashion innovations successful in the market. Accordingly, a series of questions rise: What is radical fashion? What is radical fashion innovation? What are the differences and similarities between these, and how are they connected? This study seeks to address these questions, using a foundation developed in the radical product innovation literature. Fashion innovations may be in terms form or function, or style, and can be radical (involving the breaking down of old ideas) or incremental (involving the evolution of new ideas from old ideas). We draw from the radical product innovation literature to build two related models. The first is a model of radical fashion and radical fashion innovation that illustrates the components of both concepts. The second is a model of radical fashion innovation diffusion, drawn from the general product innovation diffusion literature, which explores the evolution of and the connections between these two concepts from the beginning (i.e., the radical fashion) to the end (i.e., success in the mass market). Radical fashion may result in designs that are more suitable for the runway, catalogues, or even museum display, than for actual wear. Radical fashion has sometimes been called “new ideas before their marketing phase.” Radical fashion may successfully enter the market, however, and gain wide acceptance among consumers. The transition from radical fashion to radical fashion innovation is not too different from the transition from invention to innovation, which is familiar to researchers in product innovation. Notable in this transition process is the fact that, for many product innovations, what drives the first customers to purchase (the “Visionaries,” to use Moore’s terminology in his “crossing the chasm” model of innovation diffusion) may be very different from what drives the rest of the market (the “Pragmatists.”). If this “chasm” or divide between the two market segments is not recognized, the innovating firm may find that their product stalls during the diffusion process and never effectively reaches the mass market. In the case of fashion products, visionaries (such as celebrities and the fashion press) prime the market and create favorable word of mouth; yet, at the same time, less-radical, wearable designs may be seen on the runway, or may be manufactured for the mass market and sold through department stores, specialty clothing stores, or even discounters. The most successful worldwide designers instinctively know this, and can continuously produce radically innovative fashion which also usually transitions to the mass market successfully. They recognize the need to reach the visionaries successfully to generate sufficient publicity and word of mouth, and also to use product design, promotion, and distribution strategies, as well as appropriate price lining policies, to reach the mass market (the pragmatists) effectively. We conclude with generalized findings and managerial implications for firms in the fashion industry. We attempt to bring the radical innovation literature, and its understanding of the process of radical innovation diffusion in the marketplace, to the expanding discussion of fashion marketing success strategic development.

A comparative study of cotton knitted fabrics and garments produced by the modified low twist and conventional ring yarns

Spirality is one of the major potential problems in knitted fabrics and garments. It affects the aesthetics and physical properties of the garment produced, such as the seam displacement, shape retention, pattern distortion and sewing difficulties. In this paper, a comparative study has been carried out to evaluate the physical performance of 100 % cotton knitted fabrics and garments produced by the modified low twist and conventional ring yarns through the actual wearing and washing trials. Experimental results showed that the properties of side seam displacement, fabric spirality, dimensional stability and skewness change of the T-shirts and sweaters made by the modified single yarns are comparable to those of garments made from the control plied yarns but much improved when compared to those from the control single yarns. In addition, the pilling resistance and bursting strength of the knitted fabrics made by the modified single yarns can still maintain a reasonably high level at a low yarn twist.

Determination of the Wear of Internal Combustion Engine Components Based on Measurement of the Oil Spectrum

Spectroscopy is commonly used to analyse the wear of internal combustion engines. However, it can only measure the density of elements in abrasive dusts mixed in lubricants and not the exact amount of wear of specific engine components. In this paper, measurement of the oil spectrum is used to obtain the concentrations of elements in a lubricant. An appropriate numerical method is developed to process the acquired data and to obtain the actual wear of each running component. Experiments are conducted to verify the efficiency of this method.

A Comparison between Japanese and Japanese American Elderly Women's Dressing Consciousness and Actual Wearing Condition

A Comparison between Japanese and Japanese American Elderly Women's Dressing Consciousness and Actual Wearing Condition

An exploratory study

PurposeThis study sets out to explore the application of psychological research methods (as yet not applied) in the fashion arena. The aim of this project is to quantify, formalise and explore the causal relationships between clothing style, preference, personality factors, emotions and mood with a view to a better understanding of the psychological profile of the fashion consumer.Design/methodology/approachUsing a uniformly composed sample of females, explorative quantitative research was carried out. Two sets of questionnaires were administered to the sample to examine emotion, mood and personality before trying on a set of eight garments categorized according to style; and again afterwards to examine emotion and mood while wearing each outfit. Photographs of participants were taken wearing each of the outfits. Participants then ranked the eight outfits in order of preference. SPSS analysis identified relationships and preference indicators.FindingsThe results indicated strong relationships between mood and significant relationships between three out of five personality factors and clothing style preference; mood was a significant predictor of preference, whilst personality was moderate.Research limitations/implicationsThe research methodology necessitated lengthy time commitments from the participants and therefore limited the sample size, making generalization difficult. Based on the findings, the research requires further exploration of methods for practical application with a larger sample size.Practical implicationsPersonality, emotion and mood were shown to be managed and reflected through clothing with implications for assistance in consumer clothing decisions, service training, and strategies for personal shoppers, market segmentation and design.Originality/valueThe methodology derived from a combination of research methods coupled with actual wearing experience, previously not studied together. This is original and demonstrates how important this combination is in order to fully appreciate the psychological profile of the fashion consumer.

다물체 동역학 모델을 이용한 종이컵 성형기용 배럴캠의 마모 인자에 관한 연구

The barrel cam, which is a type of cylindrical cam, has been widely used as a part of index drive units for automatic manufacturing machines. The axis of rotation of the barrel cam is orthogonal to the axis of rotation of the follower. The index drive rotates or dwellsdepending on the cam profile, while the cam rotates with a constant velocity. Continuous sliding contact between the barrel cam and the follower surfaces causes wearing of the adhesive between them. This study shows that the contact force between two sliding bodies is responsible for the wear of the barrel cam in the paper-cup-forming machine. This contact force is calculated by using the multibody dynamics model of the paper-cup-forming machine. The analytical result is validated by comparing it to the actual wear spots on the real product.

비만 여성의 기성복 바지 착용실태 및 선호 디자인

This study details the actual wearing conditions and favored design of ready-made pants for obese women, particularly for those in their twenties and thirties. The actual problems that customers feel and the preferred design of pants were suggested based on the survey and from the standpoint of consumers. The findings of the survey are as follows. The actual wearing conditions in the survey, 80.5% like wearing pants. The main reason to prefer pants is that pants are more convenient for social or professional work activities. The main reason to avoid wearing pants is that the pants (in general) do not mask an obese body shape. The most favored was Denim/Elastic and the second most favored was Cotton/Elastic from the survey. On average, elastic materials are preferred over non-elastic materials. The reason was the comfort in wearing and convenience in social or professional activities that could mask obesity. In terms of the style, the most favored was blue jeans and the second favored was semi-formal. A straight-silhouette is the most favored as it was able to help mask obesity. The most favored position for the waistline is 4 cm lower than the natural waistline. The most favored pant length is where the pants slightly touch the floor when they stand with shoes on. For obese women the pants development that covers the weak points of the body shape giving, which is comfortable and active are desired.

한국 성인여성의 브래지어 착용 및 구매실태 조사연구 - 20대 전반 여대생을 중심으로 -

This study helps in the production of brassieres suitable for female adults by researching the actual wearing conditions and purchasing status, satisfaction rate, and preferences of female college students in their early 20`s. The collected data was analyzed by a SPSSWIN 13.0 Program and the results of the research are as follows. 1. There is a noticeable difference between the breast satisfaction rate and breast size, in addition the satisfactory rate was higher in the normal breast size or a little ample size than in the very small or very big size. According to the shape, the satisfactory rate for the breast appeared to be high in the case of the recognition and evaluation of the hemisphere type than the flat, cone, pop out, and downward type. 2. For fitness, the looseness at the top of the cup (pressed between the breasts at the upper part of the front middle), pressing and looseness at the upper sides of the cup, inappropriate size of the cup, tightness of the wings, tightness at the bottom round of the breasts, the narrow width of the wire, wide space of the shoulder strings, and the sliding of the shoulder strings had problems that needed improvement. 3. The major priorities for purchasing brassieres are size, fitness, and aesthetic qualities. As a result, the size and the fitness are more important than the trend or decorations since the brassiere has the function to support the breasts that shows that hygiene and sanitation are recognized as an important standard for undergarment selection. The size and the fitness are important factors regardless of breast types in the examination of the selection standards of the brassieres for each breast type, but the cone and hemisphere types have higher preferences for design; the pop out type has more considerations for the material of the cloth. The result show that appearance is more important for smaller breasts, but the functionality of the brassier is more important than the appearance for medium and larger breast sizes.

기능성 등산복의 착용실태 조사

본 연구는 기능성 등산복의 착용실태를 조사하여 등산복의 개발과 차별화에 기여하고자 하였다. 등산을 즐기는 107명의 응답자들이 본 설문조사에 응해주었고 문항은 개인정보, 구매습관, 등산복 선택시 가장 중요하게 여기는 기능, 본인이 소유한 등산복의 기능에 대한 만족도, 자유기술의 5개 항목으로 이루어져 있었다. 응답자들은 기능성 등산복을 선택할 때에 가장 중요하게 여기는 특성으로 흡습속건성, 보온성, 방수방풍성, 스트레치성 기능을 열거하였다. 이 기능들은 한 겹의 의복으로 착용하기보다는 여러 겹 겹쳐입을 경우 특히 그 효과가 증대한다 할 수 있다. 그리고 스트레치성의 경우 하체의 움직임이 많은 등산 활동 시 하의에 특히 필요한 기능이라 응답하였다. 그리고 응답자들은 기능성 등산복의 가격이 너무 비싸다고 응답하였으며 세탁이 불편하다고 답하였다. 이러한 설문결과로 보아 기능성 등산복의 개발 시 소비자들이 중요하게 여기는 기능을 고려해야 할 뿐만 아니라, 세탁성이나 가격과 같은 소비자들이 개선을 원하는 요소들에 대한 고려도 필요할 것이다. This study investigates the actual wearing conditions of functional mountaineering garments in Korea and provides suggestions on the development of more effective functional mountaineering garments through the examination of consumer data. This survey was based on 107 respondents who enjoy mountaineering and was composed of 5 sections consisting of personal information, purchasing habits, essential features for mountaineering garments, satisfaction levels based on features and functions, and additional comments on the improvement of mountaineering garments. Respondents said that essential features for mountaineering garments are quick absorbing/drying, insulation, water and wind proof, and elasticity. These properties become more effective when users wear mountaineering garments in layers. They want lower prices and easy to wash garments. Therefore, it is necessary to consider not only the main functions, but also the needs of consumers for easy washing and price.

Characterization and prediction of abrasive wear of powder composite materials

Composite materials produced by powder metallurgy provide a solution in many engineering applications where materials with high abrasion and erosion resistance are required. The actual wear behaviour of the material is associated with many external factors (particle size, velocity, angularity, etc.) and intrinsic material properties (hardness, toughness, Young modulus, etc.). Hardness and toughness properties of such tribomaterials are highly dependent from the content of reinforcing phase, its size and from the mechanical properties of the constituent phases. In this study an attempt is made to model the erosion wear behaviour of composite materials, to calculate the wear rate and to correlate erosion rates with experimental results and material parameters. Powder composites cermets and metal–matrix composite materials reinforced with different content of hard phase were used as examples in this research. Wear mechanisms of materials were investigated. Following from the main mechanisms of erosion wear the models of plastic deformation and brittle fracture are developed for prediction of erosion of powder composite materials. It was demonstrated, that the erosion rate of hardmetal-type materials can be predicted using the results obtained by microindentation methods. The use of hardness distribution parameters is justified with materials with low binder content.

Steady friction state and contact models of asperity interaction

One of the important problems in tribology is the evaluation of contact and wear modes under different contact conditions. A deformation predicted by contact models should correspond to an actual wear mode. The aim of this work is to compare the deformation of metallic materials in a steady friction state using contact models and a description of the dislocation structure. In order to analyze the behavior of materials under repeated sliding, the steady friction state was characterized. It was shown that the steady friction state is characterized by reaching a saturated state where a balance between hardening and relaxation of dislocations in high-deformed layers and by an equilibrium between deformation and fracture due to wear particle detachment, is exhibited. Based on an analysis of the dislocation structure of high-deformed layers in steady friction state, it was found out that the asperity contacts enable elastic deformation in macroscopic scale, whereas plastic deformation of wall-cell structure and the accommodation of substrate grain layers is reached in microscopic and mesoscopic scales. It is suggested that the hardness or yield strength and the radius of hemispherical asperity of soft metallic materials before the sliding test used in the contact models, do not reflect the deformation of asperity contact in the steady friction state. It was concluded that the development of the dislocation dynamics of surface layers under repeated sliding while taking into account the real asperity contact in steady friction state, can advance the analysis of the transition from one contact/wear mode to another.