Papers by Keyword: Blank Holder Force (BHF)

Abstract: Forming Fiber Metal Laminates (FMLs) is still challenging. There are some inherent limitations to forming smaller and complex-shaped FML parts. In particular, the process parameters have a major impact on the final FMLs part. In this paper, several investigations were conducted to optimize these process variables. In the investigations, different Blank Holder Gap (BHG) thicknesses were used to predict the optimal range; variable Blank Holder Force (BHF) and Cavity Pressure (CP) were chosen to make the results more convincing. Based on the numerical analysis, it is found that the optimum BHF should be between 10 to 15 KN; CP has a range from 8 to 10 MPa; optimum BHG should be 1.0 mm. And through using these predicted process parameters, a successful Glare cup has been formed. Furthermore, the forming performance of the Glare material is improved and the laminate has shown better formability. Finally, optimized process variables can be used for mass production of FMLs parts.

Abstract: BHF is an important technical parameter in sheet metal forming, its main function is controlling material flowing，avoiding wrinkling and fracture. The status of study on the control technology of variable blank holder force (VBHF) was summarized, focusing on the method of optimized controlling and the theory of developing trend of VBHF is introduced in the paper.

Abstract: To satisfy the local forming need of sheet-metal part, numerical simulation of SUS304 stainless steel deep-drawing with trilateral constrained slot were carried out by employing the analytical software ETA/dynaform5.5. The influence of different friction coefficient and holder force on the forming quality was analyzed by taking the inflow volume while parts forming 50mm as standard. The results show that the effect of trilateral constraint on the uneven flow and deformation of flange. And some measures were illustrated to improve the quality of some of these parts.

Abstract: Blank-holder Force (BHF) control technology is an important guarantee for the quality of parts forming. Taking YJ28E—1000/1600Q hydraulic press as object, a hydraulic fuzzy control model based on self-tuning fuzzy-PID is built to deal with the undesirable dynamic response and the low steady-state precision of the hydraulic control system. The look-up table for optimal control parameters is generated from MATLAB Toolbox. A simulation study of the system shows that the dynamic response and steady-state precision is improved greatly by adopting this kind of self-adaptive fuzzy-PID controller.

Abstract: TWB and its forming technology play important role in lightweight manufacturing for the automobile parts. The weld-line movement during TWB forming process affects the product quality greatly. In this paper, two main influence factors of the movement, BHF and the blank thickness at the both sides of the weld-line, were studied by both the experiments and finite element simulation. The results showed that BHF has significant impact on the weld-line movement, especially when the thickness difference of the blanks in TWB is beyond a certain range. Besides, suitable BHF and thickness of the blanks can not only control the weld-line movement, but also improve the formability of TWB.

Abstract: Experimental research on stamping of wrought aluminum alloy has been an important issue at home and abroad. In this paper, taking stamping of aluminum alloy hemispherical components for example, the effects of blank holder force (BHF) on stamping forming process of aluminum alloy are explored by methods of experiments and numerical simulation. Through experiments, the forming laws of hemispherical components are found out. The research shows that the BHF has significant effects on the quality of stamping components and reasonable BHF can greatly improve the formability of hemispherical components. Additionally, by applying simulation software in stamping, the development circle of product and its moulds can be shortened, and product quality and its competitiveness in the market can be improved.

Abstract: The repression of wrinkling during sheet metal forming has been a significant issue in recent years. In order to provide a reliable and efficient tool to predict the critical blank holding force to prevent wrinkles, an axi-symmetric analytical model for flange wrinkling is introduced here. Using a conventional theory of the critical condition, the critical blank-holding force and wave numbers are numerically predicted. Comparison between the numerical and experimental results shows excellent agreement for various blank dimensions and materials.