A NEW MINIMAL PART BREAKUP BODY-IN-WHITE DESIGN APPROACH AND OPTIMIZED MATERIAL MAP STRENGTH ASSESSMENT

2016 ◽  
Vol 78 (7) ◽  
Author(s):  
Mohan Rajasekaran ◽  
V. Hari Ram ◽  
M. Subramanian
Keyword(s):  
Upper Body ◽  
Vehicle Body ◽  
Load Path ◽  
Strength Assessment ◽  
Stiffness Analysis ◽  
Body In White ◽  
Weight Design ◽  
Efficient Option ◽  
Torsion Stiffness ◽  
Better Than

Body-in-White (BIW) is the Car Body without additional subsystems. Automakers are trying hard to reduce the mass of the vehicle body. The efficient option is to use multi materials and minimal number of parts in the BIW, in order to meet the stiffness requirements considering different load cases. Bending Analysis and Torsion Stiffness Analysis was performed to understand and assess the structural performance of the BIW. This paper presents the new BIW architecture with minimal number of parts, with an effective load path for the Structural and Crash load cases. Structural bending and torsion stiffness of the BIW were performed to evaluate the stiffness of the BIW to meet the passenger segment car.  The methodology of using different materials for upper and under body has been investigated with the alternatives as Aluminium and Magnesium. BIW was analysed with Steel under body and Magnesium or Aluminium upper body. The Torsion stiffness of Steel/Magnesium BIW was found to be better than Steel/Aluminium BIW. The design concept with Steel underbody and Magnesium upper body was giving lighter weight design with better structural stiffness as compared to the Steel/Aluminium body. This approach of modifying the materials for the upper body of the BIW can be considered as lightweight solutions in other Conceptual BIW designs.

Experimental Analysis of Static Stiffness for Vehicle Body in White

2012 ◽  
Vol 248 ◽  
pp. 69-73 ◽  
Author(s):  
Shu Ming Chen ◽  
Xue Wei Song ◽  
Chuan Liang Shen ◽  
Deng Feng Wang ◽  
Wei Li
Keyword(s):  
Test Bench ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Vehicle Body ◽  
Torsional Angle ◽  
Static Stiffness ◽  
Torsional Deformation ◽  
Automotive Body ◽  
Body In White ◽  
Stiffness Characteristics

In order to know the static stiffness characteristics of the vehicle body in white, the bending stiffness and torsional stiffness of an automotive body in white were tested on a test bench of the static stiffness of an automotive BIW. The bending stiffness and bending deformation of the bottom of the BIW were determined. Also, the torsional stiffness and torsional deformation of the bottom of the BIW were obtained. The fitting curves and equations between loading torque and torsional angle were acquired at clockwise and counterclockwise loading, respectively.

Optimization of the Global Static and Dynamic Performance of a Vehicle Body by Means of Response Surface Models

2012 ◽  
Author(s):  
Pavlina Mihaylova ◽  
Alessandro Pratellesi ◽  
Niccolò Baldanzini ◽  
Marco Pierini
Keyword(s):  
Response Surface ◽  
Dynamic Performance ◽  
The Body ◽  
Vehicle Body ◽  
Fe Model ◽  
Structural Modifications ◽  
Response Surface Models ◽  
First Choice ◽  
Surface Models ◽  
Body In White

Concept FE models of the vehicle structure are often used to optimize it in terms of static and dynamic stiffness, as they are parametric and computationally inexpensive. On the other hand they introduce modeling errors with respect to their detailed FE equivalents due to the simplifications made. Even worse, the link between the concept and the detailed FE model can be sometimes lost after optimization. The aim of this paper is to present and validate an alternative optimization approach that uses the detailed FE model of the vehicle body-in-white instead of its concept representation. Structural modifications of this model were applied in two different ways — by local joint modifications and by using mesh morphing techniques. The first choice was motivated by the strong influence of the structural joints on the global vehicle performance. For this type of modification the plate thicknesses of the most influent car body joints were changed. In the second case the overall car dimensions were modified. The drawback of using detailed FE models of the vehicle body is that they can be times bigger than their concept counterparts and can thus require considerably more time for structural analysis. To make the approach proposed in this work a feasible alternative for optimization in the concept phase response surface models were introduced. With them the global static and dynamic performance of the body-in-white was represented by means of approximating polynomials. Optimization on such mathematical models is fast, so the choice of the optimization algorithm is not limited only among local-search strategies. In the current study Genetic Algorithm was used to increase the chances for finding better design alternatives. Two different optimization problems were defined and solved. Their final solutions were presented and compared in terms of structural modifications and resulting responses. The approach in this paper can be successfully used in the concept phase as it is fast and reliable and at the same time it avoids the problems typical for concept models.

Improvements in Vehicle Stiffness by Adding Internal Reinforcements

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
R. Mohan ◽  
V. Hariram ◽  
M. Subramanian ◽  
S. Padmanabhan
Keyword(s):  
Topology Optimization ◽  
Automobile Industry ◽  
Climatic Conditions ◽  
Light Weight ◽  
Low Carbon ◽  
Load Path ◽  
Bending Performance ◽  
Conceptual Design Phase ◽  
Minimal Mass ◽  
Torsion Stiffness

The world’s climatic conditions rises and there is a demand for environment friendly vehicle designs. The automobile industry strives hard to ensure low carbon emissions. This refers to the mass reduction and fuel consumption. This paper investigates to achieve the overall Body-in-white (BIW) bending and torsion stiffness performance using Topology optimization and light weight internal reinforcements. The potential opportunity of achieving light weight structure using the efficient way of defining the internal reinforcements has been investigated. BIW at the conceptual design phase has been considered for the research. Topology optimization was performed considering the roof rail and the rocker as the design space with an approach of achieving the improved torsion and bending stiffness performance. The optimized bulk head design locations have improved the BIW stiffness performance with minimal mass increase in the BIW. This method can be widely used at various stages of the BIW design to identify the weaker sections and then design the load path using internal reinforcements effectively. The optimized internal reinforcements has achieved higher torsion and bending performance with minimal mass addition.

Multi-Objective Optimization of Material Layout for Body-In-White using Design of Experiments

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Rajasekaran ◽  
V. Hari Ram ◽  
M. Subramanian
Keyword(s):  
Design Of Experiments ◽  
Structural Performance ◽  
Optimized Design ◽  
Multi Objective Optimization ◽  
Load Path ◽  
Baseline Design ◽  
Multi Objective ◽  
Body In White ◽  
Break Up ◽  
Material Layout

Vehicle mass reduction is a major area of research in the automobile industry. Various techniques like reduced part break up, section reduction, material alternatives and load path design are widely being researched across the world. This paper presents a new technique of identifying materials for the components of minimal part break-up Body-In-White (BIW) in the conceptual phase using design of experiments and multi-objective optimization. Prime focus was on the methodology to effectively consider the materials for the parts without compromising the structural performance of the target components. BIW structural load cases like bending and torsion stiffness were considered to evaluate the structural performance. Material list is used as the design variable and then sampled using design of experiments to undertake multi-objective optimization. As a result, optimal material distribution and mass savings have been achieved for the BIW parts. The optimized design performance is closer to the baseline design. The proposed methodology may be widely adopted by engineers to optimally distribute the materials for the BIW components at various stages of the vehicle design.

Topology Optimization of Electric Vehicle Body in White Based on SIMP Method

2011 ◽  
Vol 308-310 ◽  
pp. 606-609 ◽  
Author(s):  
Shu Yang ◽  
Chang Qi ◽  
Ping Hu ◽  
Zhi Yong Wei ◽  
Ying Li Wang
Keyword(s):  
Topology Optimization ◽  
Geometric Constraints ◽  
Vehicle Body ◽  
Numerical Instability ◽  
Static Loads ◽  
Simp Method ◽  
Proposed Model ◽  
Body In White ◽  
Braking Process ◽  
Moment Load

Based on Solid Isotropic Microstructure with Penalization (SIMP) method, a mathematical model for topology optimization of EV is proposed, which has design objective as minimizing compliance, with volumetric and geometric constraints. To make results more engineering value, the BIW optimization of EV takes into account not only the static loads, but also the torsion load in turning and moment load in braking process of EV. A number of implementation aspects in solving the numerical instability problem generated in optimization process are discussed, including checkboard patterns and mesh-dependency. Topology optimization of EV body in white with geometry and volumetric constraints is conducted, showing effectiveness of the proposed model.

Monocoque Vehicle Body-In-White Life Evaluation Using Torsion Endurance Test on Rig

2016 ◽  
Author(s):  
Mahalingesh Burkul ◽  
Hemant Bhatkar ◽  
Mahesh Badireddy ◽  
Narayanan Vijayakumar
Keyword(s):  
Vehicle Body ◽  
Endurance Test ◽  
Life Evaluation ◽  
Body In White

Decomposition-Based Assembly Synthesis of a 3D Body-in-White Model for Structural Stiffness

2003 ◽  
Author(s):  
Naesung Lyu ◽  
Kazuhiro Saitou
Keyword(s):  
Pareto Front ◽  
Element Model ◽  
Vehicle Body ◽  
Structural Stiffness ◽  
Multi Objective Genetic Algorithm ◽  
First Case ◽  
Trade Offs ◽  
Body In White ◽  
Minimum Distortion

This paper presents an extension of our previous work on decomposition-based assembly synthesis for structural stiffness [1], where the 3D finite element model of a vehicle body-in-white (BIW) is optimally decomposed into a set of components considering the stiffness of the assembled structure under given loading conditions, as well as the manufacturability and assembleability or components. Two case studies, each focusing on the decomposition of a different portion of a BIW, are discussed. In the first case study, the side frame is decomposed for the minimum distortion of front door frame geometry under global bending. In the second case study, the side/floor frame and floor panels are decomposed for the minimum floor deflections under global bending. In each case study, multi-objective genetic algorithm [2,3] with graph-based crossover [4,5], combined with FEM analyses, is used to obtain Pareto optimal solutions. Representative designs are selected from the Pareto front and trade-offs among stiffness, manufacturability, and assembleability are discussed.

scholarly journals The reliability and validity of novel clinical strength measures of the upper body in older adults

Hand Therapy ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 130-138
Author(s):  
Hayley S Legg ◽  
Jeff Spindor ◽  
Reanne Dziendzielowski ◽  
Sarah Sharkey ◽  
Joel L Lanovaz ◽  
...  
Keyword(s):  
Older Adults ◽  
Upper Limb ◽  
Assessment Tools ◽  
Upper Body ◽  
Minimal Detectable Change ◽  
The Novel ◽  
Precision Error ◽  
Retest Reliability ◽  
Strength Assessment ◽  
Test Retest Reliability

Introduction Research investigating psychometric properties of multi-joint upper body strength assessment tools for older adults is limited. This study aimed to assess the test–retest reliability and concurrent validity of novel clinical strength measures assessing functional concentric and eccentric pushing activities compared to other more traditional upper limb strength measures. Methods Seventeen participants (6 males and 11 females; 71 ± 10 years) were tested two days apart, performing three maximal repetitions of the novel measurements: vertical push-off test and dynamometer-controlled concentric and eccentric single-arm press. Three maximal repetitions of hand-grip dynamometry and isometric hand-held dynamometry for shoulder flexion, shoulder abduction and elbow extension were also collected. Results For all measures, strong test–retest reliability was shown (all ICC > 0.90, p < 0.001), root-mean-squared coefficient of variation percentage: 5–13.6%; standard error of mean: 0.17–1.15 Kg; and minimal detectable change (90%): 2.1–9.9. There were good to high significant correlations between the novel and traditional strength measures (all r > 0.8, p < 0.001). Discussion The push-off test and dynamometer-controlled concentric and eccentric single-arm press are reliable and valid strength measures feasible for testing multi-joint functional upper limb strength assessment in older adults. Higher precision error compared to traditional uni-planar measures warrants caution when completing comparative clinical assessments over time.

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