Papers by Author: Yuan Chuan Hsu

Abstract: After the automobile made an emergency brake or bumped by accident, the baby car seat will be deformed and cracked by great force, the baby car seat have became a very important topic for years. This study focuses on analyzing the state of baby car seat after receiving forces, propose the improvement of structure strength and safety factors, enhance the structural strength of baby car seat and improve collision resistance. The internal skeleton was a backbone of baby car seat structural design, this research utilized simulation that combined CAD software (Pro-E) with finite element analysis software (Ansys\Workbench) to analyze the bumping situation, the high-speed camera was also applied to record the bumping situation of baby car seat. The comparison between these two results was used to design the skeleton within safety seat in order to approach the anticipative structure strength. Therefore, structure analysis will enable baby car seat to reach a high level of collision resistance.

Abstract: In multi-wire flat rolling process, the error of the rolled wires in thickness was due to the roller deflection and the spring back of the rolled wire. In order to control the dimension accuracy, to know the quantity of thickness error precisely is very important. In this study, the DEFORM-3D finite element analysis software was used to simulate the multi-wire flat rolling process with the elastic-plastic deformation model, supposed the rollers as elastic body and the wires as elastic-plastic body through the rolling process. From the computer simulation results, it can be found that, the deflection of roller has the biggest effect on the dimension accuracy of wire. To control the deflection value of roller, besides roller material and the roller length, the choice of roller diameter is also very important.

Abstract: The manifolds of airbag inflator were used to be produced by sheet-metal forming. It comprised at least eleven forming stages to achieve its final shape. Uneven wall thickness and poor dimensional accuracy were the common defects because the planar anisotropy of sheet-metal caused earing on the cup rim. In this study, the cup-shape workpiece is obtained from backward-extrusion of billets, followed by two stages of end-forming of tube and three stages of hole-piercing. During the end-forming production, the tool life of the first forming stage was the most severe because it applies close-die forging to increase its rim thickness. Therefore, in addition to the design of prestressed die insert, special attendance is paid to the partition of the die insert to further alleviate the stress level. The optimization of die insert was aided by the finite element analysis of DEFORM software. The results show that by lowering the parting line, the stress level can be minimized. The tool life can therefore be improved.

Abstract: This paper presents the use of vibration measurement in conjunction with spectrum signal analysis to investigate the vibration phenomena and the dynamic response of the absorber system frame and rigid axle of a vehicle body under real road-driving conditions. Ford 1.6L sedan was selected as the vehicle body to carry out the experiments with different driving speeds. B&K PULSE dynamic signal analyzer was used to detect the vibration signal induced from the absorber system frame and rigid axle of the vehicle body in motion. The acquired on-line signals are then processed through the Fast Fourier Transform using the power spectrum density, the cepstrum method, and the overall analysis. The vibration energy attenuated from the absorber system is analyzed by comparing with that on the rigid axle excited from the road conditions corresponding to different driving speeds. Furthermore, the effects of various road conditions and driving speeds on oscillation of the vehicle body are studied. The corresponding results may be extensively treated as a guiding reference of the absorber system design and manufacturing for those vehicle manufacturing companies.

Abstract: In the deep drawing of cups, the earing defect is caused primarily by planar anisotropy in the sheet. In order to obtain the optimal products in deep drawing process, blank shape is a very important formability factor. In this study, the finite element method was used to investigate the cup height and forming force of the cylindrical cup drawing process. A finite element analysis was also utilized to acquire the designed profile of the drawn products, a reverse forming method for obtaining the initial blank’s shape according to the forward cylindrical cup drawing simulation is proposed. The design of initial blank’s shape is also confirmed to obtain the designed profile of drawn cups. The influences of the blank’s shape on the height of product, the forming force, the effective stress and the effective strain were also examined.

Abstract: The shearing processes such as the blanking and piercing of sheet metals have been often used to prepare workpiece for subsequent forming operation. The sheared plane plays an important role in the shearing products’ dimension precision and their functions. The quality of sheared plane is affected not only by the material characteristics but also by the process parameters. In the current study, the finite element method is used to investigate the shearing process of sheet metals. Then, the neural network was employed to construct the relationship model of shearing process parameters related to the fracture depth of sheared plane, such as blank holding force, die corner radius, punch-die clearance, friction factor and punch speed,. The result and approach obtained from this study would be beneficial to stamping industries because they provide the reference for the prediction of shearing process.

Abstract: The parameters such as aniotropic property, blank holder force and friction coefficient between tool and blank are not only effect on the forming force, stress and strain distribution of the worpiece, but also on the earing in products. In this paper, the finite element method is used to investigate the earing of the deep drawing process. In order to verify the prediction of FEM simulation of the earing in the cylindrical cup drawing process, the experimental data are compared with the results of the current simulation. A finite element analysis is also utilized to reduce the earing profile of the drawn products, a reverse forming method for obtaining the initial blank’s shape according to the forward cup deep drawing simulation is proposed.

Abstract: The process of precision gear forging has been developed recently because of its advantages of giving high production rates and improved strength. For complete filling up, predicting the power requirement and final face width is an important feature of the forging process. A finite element analysis is utilized to investigate the maximum forging force and final face width under different process parameters such as modules, number of teeth, and the ratio of the height to diameter of billet. The abductive network is then applied to synthesize the data sets obtained from the numerical simulation, and a prediction model is established ultimately. Employing the predictive model can provide valuable references in prediction of the forging force and final face width under a suitable range of process parameters.

Abstract: In this study, the finite element method was used to analyze comprehensively the effects of punch shape on forming the forging recess. Then, the polynomial network and genetic algorithm were combined to construct the predicted and designed system. Through this approach, we can predict the forging results formed from arbitrary shaped punches, and design the optimal punch shape for forging recess. Through the interactive verifies of modeling repeatedly, the errors resulted from modeling analysis, network prediction and genetic algorithm optimal design are extremely limited. Consequently, the predicted and designed approach of optimal punched shape for forming recess in this study could be extended to the design of more complicated and difficult formed forging die.

Abstract: In this study, the predictive model of friction coefficient using cylindrical compression was constructed through combining the finite element method and neutral networks. Namely, the related data of the materials characters, cylinder compression bulging, and how they were associated with friction coefficient was obtained by the finite element method. Based on those analysis data, the relationship model, reflecting the relationship among the materials characters such as strength coefficient and strain-hardening exponent, the compression bulging such as reduction height, expanding in upper ending, expanding in bottom ending, maximum expanding in outside diameter and the friction coefficient in workpiece/die interface, was constructed. Finally, the cross verification between finite element analysis, prediction by neutral network model and the experiments of cylindrical compression testing and ring compression testing are repeatedly checked to ensure the accuracy and reliability of the constructed model. Results of the current study indicate that their errors are extremely limited, and the developed predictive system is reliable and feasible.