Advanced Materials Research Vols. 102-104

Abstract: According to the characteristic which is more and difficult to determine about the automotive panel forming factors, based on the dynamic explicit method, taking the typical automobile front fender for example, do the simulation analysis by using of DYNAFORM. On the premise of taking springback factors into account, analog the best stamping process parameters has been optimized from the analysis results after simulation such as sheet metal forming limited drawing(FLD)and sheet metal thinning drawing.

Abstract: It is important to assembling-possibility of products for the DFA (Design For Assembling). Asembling factors is analyzed, and a matter-element model is deduced, the evaluation model of products design for assembling is established according to the extensive theory and superiority evaluating method, and the process of this method is discussed in detail. The example confirmed that the evaluating method is advanced and practicality. The present analysis is qualitative combining.

Abstract: Incremental sheet forming (ISF) is an innovative and highly flexible sheet metal forming process for small batch production and prototyping, but springback is a very important factor to influence the quality of incremental sheet forming. This paper investigates the springback mechanism of incremental sheet forming using numerical method. A three-dimensional elasto-plastic finite element model was established for the simulation of the incremental sheet forming process. In this model, the combination of dynamic explicit algorithm and the static implicit algorithm was proposed to calculate the whole forming process including springback. The results of numerical simulation, such as, the strain history and distribution, the stress state and distribution, etc., are discussed in details. Moreover, the results confirm that residual stress has been releasing during forming process, which reveal the peculiar springback characteristic of incremental sheet forming process.

Abstract: Through the analysis of the interaction form between steel balls and the material in Micro-level, the primary form in different areas confirmed and the requirement of ball grading presented. The different methods of ball grading and the different influence on the interaction between steel balls and the material clarified. At last, a clear description of the calculation method of the ball grading made through an example.

Abstract: Fine-blanking is an advanced and precision stamping process. Designing the construction die is an important part of the entire development process. But for lots of special and complicated structures of fine-blanking dies, especially some progressive dies, many problems occurred during the traditional two-dimensional design method, such as heavy workload, time-consuming, difficulty of modification, difficulty of checking interference, difficulty of novice entry. To solve these problems, a rapid parametric CAD system based on SolidWorks is developed for fine-blanking progressive dies in the present study. The system comprises five modules, namely DIEBASE, WORKPART, STANDARD, MOTION and DRAWING. The first three modules are designed for the rapid designing and modeling of three different sets of die components. These modules work in tandem with the design-table-based standard part libraries. The MOTION module is designed to simulate the movement situation and check the interferences of the die structure. The last module is designed for the drawing documents of the die parts and assembly. The main feature of the system is its parameter-based interfacing for fine-blanking progressive die design. The design and modification jobs could be done easily and quickly by operating this system, and the system is easy to learn for semiskilled and even unskilled engineers. An illustrative example is demonstrated to show the usefulness of the system.

Abstract: Information of initial flat blank and final workpiece is prerequisite and satisfactory blank configuration and thickness distribution can be obtained, which is very important at the preliminary design stage. The theory and improvements of inverse analysis method of sheet metal forming based on deformation theory of plasticity is explored. In order to take into account the bending effects, this approach with CST membrane element and DKT6 plate bending element superposed to obtain the DKT12 shell element is fully introduced. An ideal reverse deformation method is implemented to improve the initial solution obtained by radical length development method. Application to a square box deep drawing case is presented with emphasis on the efficiency and usefulness of the proposed improved methods.

Abstract: Three-dimensional rapid design for mechanical products is of great importance in machinery industry. In order to enhance market competitiveness, rapid design method of case-based reasoning has been imported. This paper discusses the meaning and system of rapid design, provides a case library built up based on parametric design and knowledge base, and probes the transformation technology from three-dimensional parameterized model to two-dimensional engineering drawing with optimized view position, view scale, and drawing note position in terms of geometry, dimension and engineering restriction. The final drawing accorded with the enterprise production demand. It can greatly shorten design cycle for mechanical products, and provides a new approach for the enterprise to quickly respond to market demands.

Abstract: Starting from the planar and spatial mesh fundamental theorem, this paper puts forward a new, general and effective method for deriving the pressure-angle expressions of cam mechanisms—“Auxiliary Angle Method”. It successively overcomes the shortcomings and defects of traditional Velocity Instantaneous-pole Method’s, and is very suitable for all planar and spatial cam mechanisms. New method lay the foundations for the solution of cam mechanisms’ fundamental size tasks.

Abstract: A new method was used to analysis the performance of Nano-MAX lapping machine under working condition. Model analysis in ANSYS and operational model analysis in LMS Test.Lab are banded together properly, which reduce the calculation difficulty. Time frequency analysis method is also used to study in which speed is the most suitable one for processing of Nano-MAX lapping machine. Model analysis results reveal that 100Hz is the natural frequency of chassis and the workbench and 178Hz is the natural frequency of chassis and spindle outer covering. If the exciting frequency is 100Hz or 178Hz, there will be two mechanical parts set up resonance which will likely to cause the whole machine resonance.

Abstract: The double(unilateral)index subjection function model for part dimensional test is constructed, the checkout limit range is partitioned by process capability index, then distributing law of measure dimension is used to estimate the confidence level about part dimentional test and fits test by fuzzy theory. Finally an example is given and the proposed method proves to be feasible and valid.