Crash Analysis of Automotive Chassis Structure Considering the Strain Hardening Effect
29 Aug 2011-Vol. 1383, Iss: 1, pp 237-242
TL;DR: In this article, the effect of forming process on crash response of typical Sports Utility Vehicles (SUV) was analyzed using Hyperform and LS Dyna, and a significant change in energy absorption, peak force and stroke of the front rail was predicted.
Abstract: The work hardening during the forming process is generally ignored in crash analysis. This paper presents computational details of the effect of forming process on crash response of typical Sports Utility Vehicles (SUV). Forming results for front panels of a medium‐sized SUV were calculated using Hyperform and LS Dyna. These were imported into the crash model and crash results compared with and without the forming effects. Time taken to generate the forming data by a variety of methods is quantified and the trade‐off between time taken and accuracy is examined. LS‐DYNA was used for both forming and crash simulations. The effect of thickness, work hardening and residual stresses on the crashworthiness results is measured; crash response is seen to be significantly affected when the effects of forming are included. The paper proposes a systematic method to transfer data from the forming analysis to crashworthiness analysis (both using LS‐DYNA), allowing thickness, residual stress and plastic strain data selectively or in combination to be used to initialise the crash model. The relative effect of each of these forming parameters has been examined and the importance of, work hardening on the crash response of the stamping front rail has been identified. A significant change in energy absorption, peak force and stroke of the front rail was predicted, indicating a far stiffer response in the formed rail than would be expected based on the nominal material properties. Therefore, forming effects should be accounted for in vehicle crashworthiness predictions.
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TL;DR: In this article, the use of forming simulation output data from a hydroformed frame siderail as initial material properties for crash simulation of the component is described and correlated to test measurements.
Abstract: This paper describes the use of forming simulation output data from a hydroformed frame siderail as initial material properties for crash simulation of the component. The hydroforming simulation model is described and correlated to test measurements. Methods developed to transfer data between forming and crashworthiness analyses are presented and the limitations of the existing systems identified. The frame siderail was subjected to a representative crash load; LS-DYNA was used for both forming and crash simulations. The effect of thickness, work hardening and residual stresses on the crashworthiness results is quantified; crash response is seen to be significantly affected when the effects of forming are included.
38 citations
23 Feb 1998
TL;DR: In this article, a process that integrates the frame side rail forming analysis results into the finite element (FE) crash model was proposed, which provided material thinout, yield strength, and tensile strength which were input into the performance model.
Abstract: For body on frame vehicles, the chassis truck frame absorbs approximately 70% of the kinetic energy created from a frontal impact. Traditional performance analysis of the chassis utilizes standardized material properties for the finite element (FE) model. These steel properties do not reflect any strain hardening effects that occur during the forming process. This paper proposes a process that integrates the frame side rail forming analysis results into the FE crash model. The process was implemented on one platform at Ford Motor Company to quantify the effects. The forming analysis provided material thinout, yield strength, and tensile strength which were input into the performance model. With the modified properties, the frame deceleration pulse and buckling mode exhibited different characteristics. The integration of CAE disciplines is the next step in increasing the predictability of analytical tools. (A) For the covering abstract of the conference see IRRD E201404.
25 citations
05 Mar 2001
TL;DR: In this article, the influence of stamping process on crash response of UltraLight Steel Auto Body (ULSAB) vehicle is assessed. And the impact of forming effects included thickness variations and plastic strain hardening imparted in the part forming process.
Abstract: The objective of the research presented in this paper was to assess the influence of stamping process on crash response of UltraLight Steel Auto Body (ULSAB) [1] vehicle Considered forming effects included thickness variations and plastic strain hardening imparted in the part forming process The as-formed thickness and plastic strain for front crash parts were used as input data for vehicle crash analysis Differences in structural performance between crash models with and without forming data were analyzed in order to determine the effects and feasibility of integration of forming processes and crash models
17 citations
17 citations
11 citations