Papers by Keyword: Drawing

Abstract: Pile foundation is commonly used in modern structure of deep foundation forms. It is characteristic of good bearing capacity and lower settlement, making convenient and suitable conditions widely, etc. The pile foundation of the design calculation process is complexity. And it is time-consuming difficult manual calculation. It is not achieved satisfactory effect. Because of this, it is imperative to using computer to engineering design. Based on the analysis of the pile foundation of the space and the matrix displacement method, it is taking object-oriented programming method and Visual C++6.0 as system developing platform, parameterized drawing method. It realized the pile foundation of automatic design, analysis, calculation and drawing process. And it is achieving all the functional in the same operation platform system that it can finish from the data input to the graphics output. It greatly improves the system automation level, and improves the pile foundation design work efficiency.

Abstract: Finite element model of drawing is established and numerical simulation analysis is made based on the manufacturing status of uneven thickness distribution and frequent fracture occurrence of drawing spring seat of spiral step , and regression model of the maximum thinning rate and the maximum thickening rate of the drawn workpiece is established by taking the punch radius and clearance between punch and matrix of the workpiece as influencing factors. In addition, comprehensive quality evaluation model is created via multiobjective optimization and optimal punch radius and clearance is computed. The optimization scheme is proved to be feasible and effective through experimental verification.

Abstract: Design and analysis of computer experiments have been widely investigated. This study presents numerical procedure to optimize the sheet metal forming process. Metamodels based on responses from numerical experiments may form efficient approximations to functions in engineering analysis. They can improve the efficiency of engineering optimization substantially by uncoupling computationally expensive analysis models and (iterative) optimization procedures. This paper investigated the kriging metamodel approach. At the same time, the practical nonlinear engineering problems such as square drawing are also optimized successfully by proposed method. The results prove Kriging model is an effective method for nonlinear engineering problem in practice.

Abstract: The high-strength steel blanks with higher yield strength had introduced many challenging formability problems for the stamping process. However, in some situations the multi-stage process is a very effective solution for the stamping of high-strength blanks with a relatively lower formability than that of commonly steel blanks. In the multi-stage process, the change of strain path will be beneficial to the reduction of strain peaks and the utilization of the potential plasticity.

Abstract: Deep drawing of square boxes of tailor-welded blanks (TWBs) was studied by experiment and simulation in this paper. When the tailor-welded square boxes with different thickness was drawn to square boxes, the weld seam moved towards the thick part on the bottom and towards the thin part on the wall of square boxes. If the blank-holder force was very small, the wrinkling will happen on the thin part. If the blank-holder was very large, fracture will occur on thin part. Draw beads and non-uniform blank-holder force were investigated to control the deformation of the TWBs workpieces in this paper. When using the draw beads during TWBs drawing, using draw beads in both sides was better measures to control the movement of the weld seam. When non-uniform blank-holder force was used to control the movement of weld seam of tailor-welded blanks, it should be choice that the non-uniform blank-holder force on thick part was a half of that on thin part. It was shown that draw beads give better effects on the control of TWBs drawing than other methods. The variation of thickness was little in the bottom, and the variation of thickness was obviously in the corner of bottom. The maximal variation of thickness of TWBs workpieces on different area was both about 90.1%.

Abstract: The continuous processing technology of wool slenderizing integrated with biologic enzyme modification is introduced in this paper. Fiber fineness is obviously reduced by this technology, at the same time, wool scales are efficiently removed. Thus, wool quality is also largely enhanced. This provides favorable raw materials for the development of high added value products.

Abstract: According to the shape character of some one automobile inner panel of front fender the forming steps characterized by some process combined was brought forward. Based on FEM software the drawing process was simulated by a blank-holder force scheme 100000N, 200000N, 300000N. As the simulation results, in order to eliminate the fractures in diagonal reinforcements, it is infeasible only to decrease blank-holder force, but enlarging the die round corner is necessary. As fractures have been eliminated, in order to eliminate wrinkles, the blank-holder force needs to be increased. Otherwise the wrinkle region can be confined into useless area which needs to be cut off. Finally none forming defects occur as blank-holder force 300000N and die round corner 5mm.

Abstract: It was hard to predict crack and wrinkle which are the main failure modes when drawing for the shallow tapered parts. In this paper crack and wrinkle can be avoided effectively by using the software DYNAFORM in combination with orthogonal design of experiment method. The influence of normal anisotropy coefficient, friction coefficient, drawbead resistance and blank holding force on deep drawing shallow tapered surface was analyzed by numerical simulation. The results show that the minimum-wall-thickness was the main criterion for the drawing process but not the only criterion. Crack and wrinkle can be moderately eliminated finally after optimization of the parameters and following trim process in the drawing for shallow tapered surface.

Abstract: A finite element method is used to simulate the deep drawing processes of nickel coating with steel substrate into battery shells. The Belytschko-Wong-Chiang shell elements are used and the kinematical work hardening model is adopted, while the ties with failure contact criterion is given to the coating and substrate interface. The stress-strain field and interfacial stresses in the drawing processes are obtained. The nickel coating appeared to be yielded in the drawing processes, of which the maximum effective stress reached 241MPa, and the biggest effective strain reached 0.7524. The interfacial stresses in the coating and substrate varied during the drawing process, and their maximal values reached 40MPa in compressive state.

Abstract: It discourses the methods and procedures of drawing axonometric and intersection while AutoCAD is applied to the complication of drawing teaching material; discusses the techniques of screen-capture and the application of BetterWMF when AutoCAD is inserted into Word Documents. All of the above methods and techniques have great utility value.