Tung Sheng Yang

Application of Abductive Network and FEM to Predict the Maximum Forging Force and the Final Face Width of Spur Gear

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.

The Prediction of Earing and the Design of Initial Shape of Blank in Cylindrical Cup Drawing

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.

A Finite Element Analysis for the Forging Process of Hollow Spur Gear

The process of precision gear forging has been developed recently because of its advantages of giving high production rates, improved strength and surface finish. For complete filling up, predicting the power requirement is an important feature of the forging process. To analyze the process of incremental forging of hollow spur gear forms from initially ring-type specimens, a series of simulations using the program DEFORM-3D was carried out. The results of current simulation were compared with the experimental data those obtained by forging of hollow spur gear forms. In addition, the influences of the process parameters such as module, number of teeth, the ratio of the inner radius to the outer radius, friction factor and the height of the billet on the forging force is also examined.

Constructing the Predictive Models of Friction Coefficient Using Cylindrical Compression Testing

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.

Prediction and Design of the Optimal Punch Shape for Recess Forging

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.

Servo Forging Technology and Mold Development of the Pulley of AISI-1010 Low Carbon Steel

Aimed at AISI-1010 low carbon steel pulley components, a finite element method-based metal forming simulation software of DEFORM 3D was used to simulate and analyze the near net forging process for the low carbon steel pulley, and to design forging molds. This technology was used in the pulley tooth forging in conjunction with the servo press-based servo motion curve technology. First, the cold forging process of the pulley preform forging and the near net forging were simulated. Also, the applications of the pulse wave servo motion curve in the pulley tooth forging was simulated, which was compared with the traditional motion curve-based forging forming, where the comparisons focused on the maximum forming force and maximum equivalent stress. The results indicated that the maximum forming force and the maximum equivalent stress of the punch caused by the pulse wave servo motion curve was smaller than caused by the traditional motion curve.

Mechanical Properties and Friction of AZ31 Magnesium Alloy and Application to the Cylidrical Deep Drawing Process

The mechanical properties such as stress-strain curves and anisotropic parameters at different elevated temperatures are obtained by the computerized screw universal testing machine. The friction testing machine is used to determine the friction coefficient between die and AZ31 sheets at different elevated temperatures. 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 parameters such as stress-strain curves, anisotropic parameters, fiction coefficient and blank holder force, are as the input data during analysis. The experimental cup height compared with the current simulation result of cylindrical deep drawing process at different elevated temperature.

Friction Factor of 6061 Aluminum Alloy and Application to the Finite Element Analysis of Wheel Forging

The friction factor between 6061 aluminum alloy and die material (SKD61) are determined at different temperatures by using ring compression test which are carried out on a material testing machine. Mechanical properties and fiction factor are then applied to the finite element analysis of the wheel forging for different elevated temperature. Maximum forging load, effective stress and temperature distribution are determined of the wheel forging, using the finie element analysis. Finally, the wheel parts are formed by the forging machine under the conditions using finite element analysis.

The Surface Parameters Analysis of Magnesium Alloys Sheet during Warm Isothermal Forming

This study uses the finite element method (FEM) to predict the workpiece surface parameters, including contact area ratio and surface roughness, of asperity flattening in indentation and sliding contact for magnesium alloys sheet during warm isothermal forming. Contact area ratio and surface roughness are investigated for different process and material parameters, such as sliding distance, temperature, normal pressure and bulk strain rate by finite element analysis. The predicted results of the surface parameters from the finite element analysis are in good agreement with the results obtained from experiments.

Prediction of Surface Parameters for Strain Hardening Material of Asperity Flattening in Metal Forming

This study applies the finite element method (FEM) in conjunction with an abductive network to predict the surface parameters for strain hardening material of asperity flattening in metal forming process. To verify the prediction of FEM simulation for surface parameters, the experimental data are compared with the results of current simulation. Contact area ratio, surface roughness, skewness and kurtosis are investigated for different process and material parameters, such as normal pressure, bulk strain rate, yielding stress, strength coefficient and strain hardening exponent of surface asperity flattening in metal forming, by finite element analysis. The abductive network is then utilized to synthesize the data sets obtained from numerical simulations, and the prediction model is established for predicting surface parameters. The predicted results of the surface parameters from the prediction model are in good agreement with the results obtained from the FEM simulation.