Optimization of the structural and process parameters in the sheet metal forming process

Proceedings of the Institution of Mechanical Engineers, Part D:

2016

Self Cite

Vehicle crash optimization is a representative non-linear dynamic response structural optimization that utilizes highly non-linear vehicle crash analysis in the time domain. In the automobile industries, crash optimization is employed to enhance the crashworthiness characteristics. The equivalent-static-loads method has been developed for such non-linear dynamic response structural optimization. The equivalent static loads are the static loads that generate the same displacement field in linear static analysis as those of non-linear dynamic analysis at a certain time step, and the equivalent static loads are imposed as external loads in linear static structural optimization. In this research, the conventional equivalent-static-loads method is expanded to the crash management system with regard to the frontal-impact test and a full-scale vehicle for a side-impact crash test. Crash analysis frequently considers unsupported systems which do not have boundary conditions and where adjacent structures do not penetrate owing to contact. Since the equivalent-static-loads method uses linear static response structural optimization, boundary conditions are required, and the impenetrability condition cannot be directly considered. To overcome the difficulties, a problem without boundary conditions is solved by using the inertia relief method. Thus, relative displacements with respect to a certain reference point are used in linear static response optimization. The impenetrability condition in non-linear analysis is transformed to the impenetrability constraints in linear static response optimization.

Section: Non-linear Dynamic Response Structural Optimization and The mentioning

confidence: 99%

Non-linear dynamic response structural optimization for frontal-impact and side-impact crash tests

Lee

Proceedings of the Institution of Mechanical Engineers, Part D:

2016

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“…27 Kim and Park performed nonlinear dynamic response optimization, 28 and the research was expanded for the metal forming process. 29–31 However, ESLM has not been applied to the optimization of structures with viscoelastic materials.…”

Section: Introductionmentioning

confidence: 99%

“…ESLM has been used for the metal forming problems that have a path dependency similar to viscoelastic material and uses a few time steps. 29–32 The optimization formulations are defined for some automotive dampers. Three objective functions are proposed using the sum of damping ratios, the sum of weighted damping ratios, and the sum of squared displacements.…”

Section: Introductionmentioning

confidence: 99%

Dynamic response optimization of structures with viscoelastic material using the equivalent static loads method

Choi

Proceedings of the Institution of Mechanical Engineers, Part D:

2020

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Viscoelastic material is widely used in automotive structures due to its outstanding vibration-damping characteristics with appropriate stiffness. Viscoelastic material, which has viscosity and elasticity, shows energy absorption and dissipation. The material properties of viscoelastic material are dependent upon time, temperature, and loading path. Hence, these characteristics have to be considered when performing structural optimization. Studies on the constitutive equations of viscoelastic material are widely carried out, and structural optimization using harmonic excitation in the frequency-domain is often reported. However, structural optimization in the time-domain is rarely performed. One of the reasons is that the cost of sensitivity analysis is quite expensive. The Equivalent Static Loads Method (ESLM) is a linear/nonlinear dynamic response structural optimization method. In this research, a practical structural optimization method to consider the characteristics of viscoelastic material is proposed using ESLM. Equivalent static loads (ESLs) are defined as the static loads that generate the same displacement field as that from dynamic analysis. In ESLM, dynamic analysis and linear static response optimization are alternatively repeated until convergence is achieved. Viscoelastic material reduces the vibration amplitude and the stored energy in a structural system. Thus, excellent damping performance is required for a part with viscoelastic material, while the proper stiffness is maintained. An appropriate design formulation is made for the design of viscoelastic material. In this research, the sum of damping ratios, the sum of weighted damping ratios, and the sum of squared displacements are considered as the objective functions. These three objective functions deal with the peak displacements of damped vibration. Three case studies are defined by optimizations of some typical automotive parts with viscoelastic material. They are a sandwich panel, a rubber bushing, and a seat cushion. The damping performances of the objective functions are compared and discussed.

World Journal of Research and Review

“…Relevant research shows that reasonable process planning, reasonable drawing die surface design including drawing process supplementary surface design, blank surface design, drawing rib design, application of drawing rib [5]- [7] , setting of drawing simulation process and optimization of forming process are the key factors in multi-step stamping process design [8]- [11] . This paper takes car front panel as the research object and establishes the whole process stamping process plan, designs the whole process die surface and completes the numerical simulation and optimization of stamping process.…”

Section: Introductionmentioning

confidence: 99%

Simulation and Optimization of Multi-step Stamping Forming Process for Car Front Panel

Huang¹,

Li²

2018

Pages 01-05 1 www.wjrr.org  Abstract-Taking the front panel of a car as the research object, the whole process forming process plan of the parts is analyzed and planned. Based on this scheme, the initial sheet profile is calculated by one-step method. The whole process of stamping forming is simulated and analyzed based on AutoForm software and the forming defects are predicted and the forming process is optimized. The simulation and optimization results show that the whole process multi-step stamping simulation can obtain the process die surface quickly and effectively, and realize the seamless joint between the whole process die surface design and multi-step stamping simulation and optimization design. Reasonable product process optimization and trimming line optimization reduce the cracking phenomenon and actual boundary contour error.Index Terms-whole process, initial sheet profile, forming process optimization, multi-step stamping forming, die surface design HUANG Zhao-ming: male, lecturer, master, graduated from HeFei University of Technology, vehicle engineering. His research direction is the theory and method of modern vehicle design. Now he is the vice president of Hohai University Wentian College, College of Mechanical Engineering. He is also deputy director of the Institute of mechanical engineering and director of the office of teaching and scientific research. Over the past five years, he has chaired or mainly participated in more than 10 key scientific research projects at the provincial level, published more than 30 papers of three types or above by the first author or communication author, and authorized more than 20 patents. Social positions related to scientific research: