Research of Simplified B Pillar Model for Roof Crashworthiness

2010 ◽  
Vol 34-35 ◽  
pp. 404-409
Author(s):  
Tao Xu ◽  
Liang Hao ◽  
Yi Wen Li ◽  
Qiang Li
Keyword(s):  
Surrogate Model ◽  
Simplified Model ◽  
Concept Design ◽  
Parallel Connection ◽  
Channel Section ◽  
Early Design ◽  
Nonlinear Springs ◽  
Thin Walled ◽  
Pillar Structure ◽  
Collapse Theories

The B pillar structure, which affects automotive roof crashworthiness, must have a perfect surrogate model to satisfy the early design demands. This work aims to explore the proper approach of simplified model construction. To create the simplified B pillar, the collapse theories of thin-walled hexagonal and channel beams under bending collapse are reviewed and applied to simulate the deforming behavior. Meanwhile, the simplified model is constructed from parallel connection of curved hexagonal and channel section beams. After distributing different rotational nonlinear springs, the same crashworthiness analyses are performed on both simplified and initial FE models to verify the simplified effects. The results demonstrate the potential of the approach and process proposed in developing the simplified model for the concept design of autobody.

Design for Crashworthiness of Vehicle Structures via Equivalent Mechanism Approximations and Crush Mode Matching

2004 ◽  
Author(s):  
Karim Hamza ◽  
Kazuhiro Saitou
Keyword(s):  
Cross Sections ◽  
Surrogate Model ◽  
Time History ◽  
Fe Model ◽  
Structural Members ◽  
Direct Optimization ◽  
Nonlinear Springs ◽  
Crashworthiness Design ◽  
Thin Walled ◽  
Equivalent Mechanism

This paper presents a 3D extension to our previous work on vehicle crashworthiness design that utilizes “equivalent” mechanism models of vehicle structures as a tool for the early design exploration. An equivalent mechanism (EM) is a network of rigid links with lumped masses connected by prismatic and revolute joints with nonlinear springs, which approximate aggregated behaviors of structural members during crush. A number of finite element (FE) models of thin-walled beams with typical cross sections and wall thicknesses are analyzed to build a surrogate model that maps the beam dimensions to nonlinear spring properties. Using the surrogate model, an EM model is optimized for given design objectives by selecting the nonlinear springs among the ones realizable by thin-walled beams. The optimum EM model serves to identify a good crash mode (CM), the time history of collapse of the structural members, and to suggest the dimensions of the structural members to attain it. After the optimization, the FE model of an entire structure is “assembled” from the suggested dimensions, which is further modified to attain the good CM identified by the optimum EM model. A case study of a 3D vehicle front half body demonstrates that the proposed approach can help obtain good designs with far less computational resources than the direct optimization of a FE model.

scholarly journals Strength of Thin-Walled Lipped Channel Section Columns with Shell-Shaped Curved Grooves

2018 ◽  
Vol 08 (04) ◽  
pp. 508-523
Author(s):  
Koki Hoshide ◽  
Mitao Ohga ◽  
Pang-jo Chun ◽  
Tsunemi Shigematsu ◽  
Sinichi Kawamura
Keyword(s):  
Channel Section ◽  
Thin Walled

In-plane behavior of cold-formed thin-walled beam-columns with lipped channel section

2016 ◽  
Vol 105 ◽  
pp. 1-15 ◽  
Author(s):  
Ying-Lei Li ◽  
Yuan-Qi Li ◽  
Yan-Yong Song ◽  
Zu-Yan Shen
Keyword(s):  
Channel Section ◽  
Beam Columns ◽  
Thin Walled

Study on Machining Deformation Errors in Spiral Finish Milling of Thin-Walled Blades

2011 ◽  
Vol 314-316 ◽  
pp. 1773-1777
Author(s):  
Wei Wei Liu ◽  
Pei Chen ◽  
Xiao Juan Gao ◽  
Chen Wei Shan ◽  
Min Wan
Keyword(s):  
Geometric Dimension ◽  
Beam Theory ◽  
Milling Process ◽  
Simplified Model ◽  
Machining Deformation ◽  
Proposed Model ◽  
Thin Walled ◽  
The Relationship ◽  
Torsion Deformation

In this paper, a new procedure is proposed to study the deformation errors for spiral milling process of blade, which can be simplified as a stepwise beam based on the geometry and clamping characteristics. Kirchhoff beam theory is adopted to analyze the bending and torsion deformation. The relationship between machining deformation errors and the workpiece’s geometric dimension are also established based on the simplified model. Corresponding algorithms are realized by MATLAB codes. Experiment test shows that the results predicted by the proposed model are in well agreement with measured ones.

scholarly journals Experimental Investigations of Impact Damage Influence on Behavior of Thin-Walled Composite Beam Subjected to Pure Bending

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1127 ◽  
Author(s):  
Tomasz Kubiak ◽  
Lukasz Borkowski ◽  
Nina Wiacek
Keyword(s):  
Impact Damage ◽  
Full Range ◽  
Image Correlation ◽  
Bending Test ◽  
Beam Deflection ◽  
Experimental Investigations ◽  
Pure Bending ◽  
Channel Section ◽  
Thin Walled ◽  
The Impact

The paper deals with buckling, postbuckling, and failure of pre-damaged channel section beam subjected to pure bending. The channel section beams made of eight-layered GFRP laminate with different symmetrical layups have been considered. The specimens with initially pre-damaged web or flange were investigated to access the influence of impact damage on work of thin-walled structure in the full range of load till failure. The bending tests of initially pre-damage beams have been performed on a universal tensile machine with especially designed grips. The digital image correlation system allowing to follow the beam deflection have been employed. The experimentally obtained results are presented in graphs presenting load-deflection or load vs. angle of rotation relations and in photos presenting impact damages areas before and after bending test. The results show that the impact pre-damages have no significant influence on the work of channel section beams.

Overview and Kinetostatic Characterization of Compliant Shell Mechanism Building Blocks

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Joep P. A. Nijssen ◽  
Giuseppe Radaelli ◽  
Charles J. Kim ◽  
Just L. Herder
Keyword(s):  
Mechanism Design ◽  
Compliant Mechanism ◽  
Building Blocks ◽  
Concept Design ◽  
Spatial Mechanism ◽  
Thin Walled Structures ◽  
Spatial Geometry ◽  
Thin Walled ◽  
Compliant Mechanism Design

Abstract Compliant shell mechanisms utilize thin-walled structures to achieve motion and force generation. Shell mechanisms, because of their thin-walled nature and spatial geometry, are building blocks for spatial mechanism applications. In spatial compliant mechanism design, the ratio of compliance is the representation of the kinetostatics involved. Using shell mechanisms in concept design, however, can prove difficult without a uniform characterization method. In this article, we make use of compliance ellipsoids to achieve characterization of the ratio of compliance for shell mechanisms. Ten promising shells are presented with the kinetostatic characteristics, combined with a uniform method of determining the kinetostatic characteristics for other unknown shells. Finally, we show how shells are indeed a valid alternative in the spatial mechanism design, compared to conventional flexure mechanisms.

scholarly journals A Numerical Study of the Effect of Component Dimensions on the Critical Buckling Load of a GFRP Composite Strut under Uniaxial Compression

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 931 ◽  
Author(s):  
Quoc Hoan Doan ◽  
Duc-Kien Thai ◽  
Ngoc Long Tran
Keyword(s):  
Uniaxial Compression ◽  
Cross Section ◽  
Numerical Study ◽  
Slenderness Ratio ◽  
Thickness Ratio ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Channel Section ◽  
Gfrp Composite ◽  
Thin Walled

In the practical design of thin-walled composite columns, component dimensions should be wisely designed to meet the buckling resistance and economic requirements. This paper provides a novel and useful investigation based on a numerical study of the effects of the section dimensions, thickness ratio, and slenderness ratio on the critical buckling load of a thin-walled composite strut under uniaxial compression. The strut was a channel-section-shaped strut and was made of glass fiber-reinforced polymer (GFRP) composite material by stacking symmetrical quasi-isotropic layups using the autoclave technique. For the purpose of this study, a numerical finite element model was developed for the investigation by using ABAQUS software. The linear and post-buckling behavior analysis was performed to verify the results of the numerical model with the obtained buckling load from the experiment. Then, the effects of the cross-section dimensions, thickness ratio, and slenderness ratio on the critical buckling load of the composite strut, which is determined using an eigenvalue buckling analysis, were investigated. The implementation results revealed an insightful interaction between cross-section dimensions and thickness ratio and the buckling load. Based on this result, a cost-effective design was recommended as a useful result of this study. Moreover, a demarcation point between global and local buckling of the composite strut was also determined. Especially, a new design curve for the channel-section GFRP strut, which is governed by the proposed constitutive equations, was introduced to estimate the critical buckling load based on the input component dimension.

Buckling and postbuckling behaviour of thin-walled composite channel section column

2013 ◽  
Vol 100 ◽  
pp. 195-204 ◽  
Author(s):  
Hubert Debski ◽  
Tomasz Kubiak ◽  
Andrzej Teter
Keyword(s):  
Channel Section ◽  
Composite Channel ◽  
Thin Walled

Methodology for Global Optimization of Computationally Expensive Design Problems

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Stefanos Koullias ◽  
Dimitri N. Mavris
Keyword(s):  
Global Optimization ◽  
Objective Function ◽  
Surrogate Model ◽  
Design Space ◽  
Design Problems ◽  
Early Design ◽  
Model Based ◽  
Computationally Expensive ◽  
Fully Bayesian ◽  
Gp Model

The design of unconventional systems requires early use of high-fidelity physics-based tools to search the design space for improved and potentially optimum designs. Current methods for incorporating these computationally expensive tools into early design for the purpose of reducing uncertainty are inadequate due to the limited computational resources that are available in early design. Furthermore, the lack of finite difference derivatives, unknown design space properties, and the possibility of code failures motivates the need for a robust and efficient global optimization (EGO) algorithm. A novel surrogate model-based global optimization algorithm capable of efficiently searching challenging design spaces for improved designs is presented. The algorithm, called fBcEGO for fully Bayesian constrained EGO, constructs a fully Bayesian Gaussian process (GP) model through a set of observations and then uses the model to make new observations in promising areas where improvements are likely to occur. This model remedies the inadequacies of likelihood-based approaches, which may provide an incomplete inference of the underlying function when function evaluations are expensive and therefore scarce. A challenge in the construction of the fully Bayesian GP model is the selection of the prior distribution placed on the model hyperparameters. Previous work employs static priors, which may not capture a sufficient number of interpretations of the data to make any useful inferences about the underlying function. An iterative method that dynamically assigns hyperparameter priors by exploiting the mechanics of Bayesian penalization is presented. fBcEGO is incorporated into a methodology that generates relatively few infeasible designs and provides large reductions in the objective function values of design problems. This new algorithm, upon implementation, was found to solve more nonlinearly constrained algebraic test problems to higher accuracies relative to the global minimum than other popular surrogate model-based global optimization algorithms and obtained the largest reduction in the takeoff gross weight objective function for the case study of a notional 70-passenger regional jet when compared with competing design methods.

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