Papers by Keyword: Trimming

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Authors: Wei Wang, Ping Jiang, Jia Qi Wang, Run Hua Tan
Abstract: In the mapping from functional requirements to design parameters in Axiomatic Design, a relation model about design parameters will be discussed. According to this model, use trimming which is redefined with Axiomatic Design and Evolution Mode of TRIZ to reduce coupling. At last, a JYS - Z electric brush type filter is described to prove the process.
Authors: Zhan Yao Yang, Guo Quan Fan
Abstract: This paper introduces blanking, drawing and compound die of the cylindrical parts. The compound die applies the special structure to maintain a constant blank holder pressure, which is not increased by drawing. It reduces the processes and improves the efficiency of production.
Authors: Qiu Chong Zhang, Zhi Bing Zhang, Yu Qi Liu
Abstract: A trimming algorithm is presented for trimming process of refined meshes in sheet metal forming simulation. Firstly, trimming line is pretreated to guarantee it smooth enough for trimming process. Secondly, the elements around the trimming line are found and refined to the highest adaptive level. Thirdly, the intersection points between trimming line segment and the element edge can be obtained using an Advancing Inciting and Adjustment method. Then new number is distributed to nodes of elements on one side of trimming line so that the meshes can be divided into several parts by the trimming line. Finally physical quantities of the remained elements are inherited from the original elements. At last the validity, practicability and speediness of the algorithm are verified with a numerical experiment. And the algorithm is integrated into a sheet metal forming simulation program, FASTAMP.
Authors: Hossein Hamedanianpour, Jean François Chatelain
Abstract: Polymer matrix composites, particularly carbon fiber reinforced polymers (CFRPs) are widely used in various high technology industries, including aerospace, automotive and wind energy. Normally, when CFRPs are cured to near net shape, finishing operations such as trimming, milling or drilling are used to remove excess materials. The quality of these finishing operations is highly crucial at the level of final assembly. The present research aims to study the effect of cutting tool wear on the resulting quality for the trimming process of high performance CFRP laminates, in the aerospace field. In terms of quality parameters, the study focuses on surface roughness and material integrity (uncut fibers, fiber pull-out, delamination or thermal damage of the matrix), which could jeopardize the mechanical performance of the components. In this study, a 3/8 inch diameter CVD diamond coated carbide tool with six straight flutes was used to trim 24-ply carbon fiber laminates. Cutting speeds ranging from 200 m/min to 400 m/min and feed rates ranging from 1524 mm/min to 4064 mm/min were used in the experiments. The results obtained using a scanning electron microscope (SEM) showed increasing defect rates with increased tool wear. The worst surface integrity, including matrix cracking, fiber pull-out and empty holes, was also observed for plies oriented at -45 degrees. For the surface finish, it was observed that for the studied cutting length ranges, an increase in tool wear resulted in a decrease in surface roughness. Regarding tool wear, a lower rate was observed at lower feed rates and higher cutting speeds, while a higher tool wear rate was observed at intermediate values of our feed rate and cutting speed ranges.
Authors: Qing Liang Chen, Jing Wen Zhou, Xue Mei Chen, Yan Chen, Yu Can Fu
Abstract: Carbon fiber reinforced plastics (CFRP) laminates with different top/bottom fiber direction angle (stacking sequences of each ply) are trimmed at various workpiece inclined angles. Four types of delamination are studied and discussed. The results indicate that fiber direction has great influence on the type of delamination and the workpiece inclined angle determines the proportion of each type of delamination expect a special cast that the delamination form turns into type I/II when the workpiece inclined angle is 58.6o. Stacking sequences of each ply have great influence on the numbers of damaged plies and the 0o fiber direction ply has the ability to prevent the development of damaged ply.
Authors: Y. Antonov
Abstract: Features of application of laser trimming for normalization of accuracy of resistance of resistive elements (REs) of hybrid integrated circuits (ICs) are considered. Limitations of the applied method are determined and decisions on its development are offered on the basis of application of means of the automated designing and modelling. Application of the method of the analysis of hierarchies (MAH) and the theory of indistinct sets for an estimation and optimization of projects of normalization is proved.
Authors: Raja Izamshah, M. Akmal, Mohd Amran Md Ali, Mohd Hadzley, Mohd Shahir Kasim, Mohd Asyadi Azam, Mohd Amri Sulaiman
Abstract: Carbon Fiber Reinforced Plastics (CFRP) exhibit superior characteristics such as high specific strength, high specific modulus, fatigue strength and endurance. During the manufacture of components from CFRP, it is usually necessary to carry out a post-machining step. Generally, after curing process, the parts will be trimmed in order to meet the required tolerances. Due to the heterogeneous composition and anisotropy of composite materials, machining procedures can damage the material in ways that directly affect its mechanical properties. Currently a costly try and error approach is employed to determine the optimal process conditions. Thus, this study focused on numerical modelling of machining CFRP composites using cross-nick router. A set of machining tests were performed in order to validate the accuracy of the model. Good agreement between simulation and experimental results show the validity of the model in handling real-field problems. The proposed numerical modeling technique can be used as an input in the process planning and decision making levels.
Authors: Aude Boudelier, Mathieu Ritou, Sebastien Garnier, Benoît Furet
Abstract: The present paper proposes a methodology to optimize process parameters for trimming applications with diamond abrasive cutters. This methodology is based on the study of quality of trimmed surface, through material integrity and surface roughness, and on the study of cutting mechanisms. Their evolutions according to tool parameters and cutting conditions have been analysed. Results show that diamond grits size must be chosen according to the required surface roughness. Feedrate must respect cutting limitations due to CFRP removal mechanisms with abrasive cutters, which have been identify through analyses of specific cutting energy. Finally, a protocol in two steps is proposed to determine the optimum process parameters according to the application. Firstly, constraint functions due to respect of quality and to limiting cutting phenomena are defined. Thus, limiting values of process parameters are determined. Then, process parameters are selected in order to optimize productivity.
Authors: Dominique Daniel, Gilles Guiglionda, Pierre Litalien, Ravi Shahani
Abstract: Cost-efficient designs of aluminum autobody structures consist mainly of stampings using conventional technology. Progress in metallurgy and forming processes has enabled aluminum body panels to achieve significant market share, particularly for hoods. Fast bake hardening alloys with better hemming performance were developed for improved outer panel sheet products. Specific guidelines for handling and press working were established to form aluminum panels using similar schedules and production lines as steel parts. Stamping productivity was improved by optimization of the trimming process to reduce sliver/particle generation and resulting end-of-line manual rework. Both hemming formability and trimming quality not only depend on tooling setup but also on microstructural features, which govern intrinsic alloy ductility. Targets for the next high volume aluminum car body applications, such as roof panels and doors, require higher strength and/or better formability. The challenges of complex stampings can be met with optimized alloys and lubricants, with improved numerical simulation to fine-tune stamping process parameters, and with the introduction of new technologies. Warm forming was examined as a potential breakthrough technology for high volume stamping of complex geometries.
Authors: S.F. Golovashchenko
Abstract: Small pieces of metal are generated during trimming of automotive body panels. Commonly referred to as slivers, these pieces can be imprinted into the surface of stamped panels. This may require metalfinish of every stamped exterior panel. The objective of the paper is to study the influence of trimming conditions on quality of trimmed surface and to modify the trimming process to eliminate slivers and burrs from the trimmed surface. Suggested solution includes two measures: 1) building an elastic support of the offal eliminating bending of the area of the blank being trimmed off; 2) creating the preference of crack propagation from the lower shearing edge by machining a small radius on the upper shearing edge.
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