Finite Element Dynamic Analysis of an Automotive Frame

The flexibility of welded joints is an important issue in structural analysis and design of car bodies. Two three-dimensional, design-oriented models (uncoupled and coupled) are developed to represent the complaint behavior of multibranch flexible joints. The uncoupled model consists of torsional springs restraining the relative rotation of the joint branches in the three planes, while all branches are assumed to be rigidly connected in translation. Coupling between motions in different planes is neglected. The coupled model accounts for such coupling. A statistical system identification method is proposed for inferring the model parameters from the static response of the structure. The method is demonstrated by applying it to a simple cube frame structure and a car body. Finally, the two models are compared in terms of their ability to predict static response. NomenclatureComplex = strain energy of complex model E m = error vector Simple = strain energy of simple model F = force vector F R = reduced force vector K = stiffness matrix Kj = joint stiffness matrix overall = overall stiffness matrix K R = reduced stiffness matrix of structure without the joint KU = stiffness matrix of unconstrained joint kij = elements of joint stiffness matrix kj = joint stiffness parameter vector L f = length of force vector U = displacement vector U A = vector of actual displacements U E = strain energy stored by the springs U m = measured displacement vector u = rotation vector V m = covariance matrix of measurement errors X m = matrix formed from the measured displacements 6 iy = rotational degrees of freedom at joint

show abstract

“…Then, we update k } by obtaining a weighted resic regression solution for Eq. (6). The solution is given by following formula,…”

Section: Fig 2 System Identification Solution Proceduresmentioning

confidence: 99%

“…One possible approach is to use test results to identify joint characteristics. For example, Boroski et al 6 introduced fictitious linear springs to represent the flexibility of joints. Their analysis assumes various spring constants, and then those constants are tuned to make theoretical predictions match dynamic test results.…”

Section: Introductionmentioning

confidence: 99%

Probabilistic system identification of two flexible joint models

1991

View full text Add to dashboard Cite

show abstract

“…Some research efforts have been conducted to determine joint flexibility. For an optimal automotive body design, conceptual joint models incorporating elastic rotational and torsional springs into a finite element beam model of an automotive frame have been proposed (Borowski et al, 1975;El-Sayed, 1989;Cameron et al, 1997Cameron et al, , 2000Lee and Nikolaidis, 1998). In addition, semi-rigid framing of a rotational joint with a moment-rotation relationship has been developed to simulate the actual structural response of steel frames as elasto-plastic hinges (Chen, 2000;Faella et al, 1999).…”

Section: Introductionmentioning

confidence: 98%

In-plane mechanical behaviors of 2D repetitive frameworks with four-coordinate flexible joints and elbowed beam members

Tanaka

Shibutani

2009

Journal of the Mechanics and Physics of Solids

View full text Add to dashboard Cite

“…Borowski et al [7] found that the complex joints conditions with shell finite element models. The validated analytical model is used for studying the on the vehicle frame have a significant effect on the dynamic behaviour of the frame.…”

Section: Introductionmentioning

confidence: 99%

Analysis of thin-walled frames considering joint flexibilities

Marur

2007

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

Analytical models are developed for static and dynamic analysis of thin-walled frames representing the automotive side structures. The model is based on one-dimensional beam theory that considers joint flexibility to compute stiffness and frequency response of the whole frame structure. The computed out-of-plane displacements under static and impact loading are in good agreement with those obtained from the shell finite element method. Using the validated analytical model, the influence of joint flexibility on the elastic response of the side structure is studied.

show abstract

Finite Element Dynamic Analysis of an Automotive Frame

Cited by 17 publications

References 2 publications

Probabilistic system identification of two flexible joint models

Probabilistic system identification of two flexible joint models

In-plane mechanical behaviors of 2D repetitive frameworks with four-coordinate flexible joints and elbowed beam members

Analysis of thin-walled frames considering joint flexibilities

Contact Info

Product

Resources

About