Design and Analysis of Automotive Bumper Covers in Transient Loading Conditions

2016 ◽  
Vol 715 ◽  
pp. 174-179 ◽  
Author(s):  
Chih Hsing Liu ◽  
Ying Chia Huang ◽  
Chen Hua Chiu ◽  
Yu Cheng Lai ◽  
Tzu Yang Pai
Keyword(s):  
Optimal Design ◽  
Numerical Model ◽  
Design Method ◽  
Experimental Tests ◽  
Cost Effective ◽  
Limited Range ◽  
Optimization Approach ◽  
Loading Conditions ◽  
Element Analysis ◽  
Design Guideline

This paper presents the analysis methods for design of automotive bumper covers. The bumper covers are plastic structures attached to the front and rear ends of an automobile and are expected to absorb energy in a minor collision. One requirement in design of the bumper covers is to minimize the bumper deflection within a limited range under specific loadings at specific locations based on the design guideline. To investigate the stiffness performance under various loading conditions, a numerical model based on the explicit dynamic finite element analysis (FEA) using the commercial FEA solver, LS-DYNA, is developed to analyze the design. The experimental tests are also carried out to verify the numerical model. The thickness of the bumper cover is a design variable which usually varies from 3 to 4 mm depending on locations. To improve the stiffness of the bumper, an optimal design for the bumper under a pre-defined loading condition is identified by using the topology optimization approach, which is an optimal design method to obtain the optimal layout of an initial design domain under specific boundary conditions. The outcome of this study provides an efficient and cost-effective method to predict and improve the design of automotive bumper covers.

scholarly journals Stiffness Analysis of Rectangular Isolators Reinforced by Engineering Plastics

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Han Liu ◽  
Ping Tan ◽  
Fulin Zhou
Keyword(s):  
Finite Element Analysis ◽  
Experimental Tests ◽  
Cost Effective ◽  
Seismic Protection ◽  
Fiber Reinforced ◽  
Poisson Effect ◽  
Element Analysis ◽  
Stiffness Analysis ◽  
Engineering Plastics ◽  
Improve Calculation

A novel cost-effective isolator reinforced by engineering plastics has been designed and manufactured for seismic protection for low-rise buildings in less developed areas. The reinforcement is flexible in tension, which is similar to fiber-reinforced isolators. However, available solutions for fiber-reinforced isolators are not applicable, because the Poisson effect of engineering plastics cannot be neglected, which is done for fiber reinforcement. In this paper, analytical solutions for compression and bending stiffness for rectangular isolators reinforced by engineering plastics are proposed, with both the Poisson effect of the reinforcement and the effect of rubber compressibility taken into consideration. Then, the simplified solutions are also derived, which can greatly improve calculation efficiency. To validate the solutions, finite element analysis is conducted on a set of isolators with different reinforcement stiffnesses. The results show the superiority of the proposed solutions to the previous solutions for fiber-reinforced isolators. A series of experimental tests of the isolators are also carried out to verify the solutions. Both the analytical and the simplified solutions match well with the experimental results.

Limit and Burst Pressures for a Cylindrical Vessel With a 30 deg—Lateral d/D⩾0.5

2005 ◽  
Vol 127 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Z. F. Sang ◽  
Y. J. Lin ◽  
L. P. Xue ◽  
G. E. O. Widera
Keyword(s):  
Internal Pressure ◽  
Design Method ◽  
Limit Load ◽  
Diameter Ratio ◽  
Cylindrical Vessel ◽  
Pressure Loading ◽  
Element Analysis ◽  
Design Guideline ◽  
Burst Test ◽  
The Finite Element Analysis

The purpose of this paper is to provide research results for a cylindrical vessel—30 deg lateral intersection with diameter ratio d/D⩾0.5 under increasing internal pressure loading. The results include those from tests as well as from an inelastic stress analysis. The experimentally determined limit load is compared with that from the finite element analysis. The stress concentration factor, the spread of the plastic area, and the behavior of the deformation are provided. Also, a burst test of the model vessel is carried out to provide some data to justify the existing design method and forms a basis for developing an advanced design guideline for cylindrical vessel—lateral intersection under internal pressure loading.

Robust Design of Bistable Compliant Mechanisms Using the Bistability of a Clamped-Pinned Beam

2008 ◽  
Author(s):  
Young Seok Oh ◽  
Sridhar Kota
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Loading Conditions ◽  
Element Analysis ◽  
Bistable Behavior ◽  
Stable Position ◽  
Straight Beam ◽  
Free Beam

Our research investigates a new approach to design of bistable compliant mechanisms using the bistability of a clamped-free beam. Bistability plays an important role for a variety of applications since energy is applied only to move the mechanism from one stable position to another and no energy needs to be expended once a stable position is reached. Behavior of a bistable compliant mechanism, in general, is highly non-linear and relies on the buckling phenomenon. Normally, buckling is very sensitive to imperfections in manufacturing processes, operating conditions and boundary conditions. We present a method for designing bistable mechanisms that are robust against such imperfections by utilizing the behavior of a simple clamped-free beam. A solution for large deformation of a simple clamped-free beam is first obtained to study its bistable behavior under various loading conditions. If the load is greater than the critical buckling load, the beam can be deflected not only in the normal direction but also in a ‘reverse-lateral’ (RL) direction. First, an initially straight beam must be bent to a certain curvature under the action of the applied force. In the second loading condition, the partially bent beam is further loaded so that it buckles in the RL direction into a stable position. The magnitude and direction of the forces in both loading conditions that are conducive to bistability are thus determined. A compliant mechanism is then designed such that its output generates desired forces on the beam to deform it in the RL direction. We demonstrate that the RL deformation is less sensitive to the imperfections and ensures bistable behavior. Using clamped-pinned beams, two design examples (symmetric and asymmetric cases) of bistable compliant mechanisms are presented. Results show very good correlation between the finite element analysis and experimental tests on prototypes.

An Optimal Design Method for Reducing Brake Squeal in Disc Brake Systems

2007 ◽  
Author(s):  
Toru Matsushima ◽  
Shinji Nishiwaki ◽  
Shintarou Yamasaki ◽  
Kazuhiro Izui ◽  
Masataka Yoshimura
Keyword(s):  
Optimal Design ◽  
High Performance ◽  
Optimization Problem ◽  
Design Method ◽  
Performance Measure ◽  
Disc Brake ◽  
Analysis Model ◽  
Brake Squeal ◽  
Element Analysis ◽  
Optimal Design Method

Minimizing brake squeal is one of the most important issues in the development of high performance braking systems. Recent advances in numerical analysis, such as finite element analysis, have enabled sophisticated analysis of brake squeal phenomena, but current design methods based on such numerical analyses still fall short in terms of providing concrete performance measures for minimizing brake squeal in high performance design drafts at the conceptual design phase. This paper proposes an optimal design method for disc brake systems that specifically aims to reduce brake squeal by appropriately modifying the shapes of the brake system components. First, the relationships between the occurrence of brake squeal and the geometry and characteristics of various components is clarified, using a simplified analysis model. Next, a new design performance measure is proposed for evaluating brake squeal performance and an optimization problem is then formulated using this performance measure as an objective function. The optimization problem is solved using Genetic Algorithms. Finally, a design example is presented to examine the features of the optimal solutions and confirm that the proposed method can yield useful design information for the development of high performance braking systems that minimize brake squeal.

scholarly journals Modeling and Optimal Design for a High Stability 2D Optoelectronic Angle Sensor

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4409 ◽  
Author(s):  
Cheng ◽  
Liu ◽  
Xu ◽  
Li ◽  
Fan ◽  
...  
Keyword(s):  
Optimal Design ◽  
Environmental Changes ◽  
Design Method ◽  
Low Cost ◽  
High Precision Measurement ◽  
Element Analysis ◽  
Angle Sensor ◽  
Structural Deformations ◽  
Optimal Design Method ◽  
The Stability

The structural deformations caused by environmental changes in temperature, vibration, and other factors are harmful to the stability of high precision measurement equipment. The stability and optimal design method of a 2D optoelectronic angle sensor have been investigated in this study. The drift caused by structural deformations of the angle sensor has been studied and a drift error model has been achieved. Key components sensitive to thermal and vibrational effects were identified by error sensitivity analysis and simulation. The mounts of key components were analyzed using finite element analysis software and optimized based on the concept of symmetric structures. Stability experiments for the original and optimized angle sensors have been carried out for contrast. As a result, the stability of the optimized angle sensor has been improved by more than 63%. It is verified that the modeling and optimal design method is effective and low-cost, which can also be applied to improve the stability of other sensors with much more complex principles and structures.

Strength Optimization of Infant Pop-Up Seat Frame Using Discrete Material and Thickness Optimization

2021 ◽  
Vol 11 (3) ◽  
pp. 1-20
Author(s):  
YeongJo Ju ◽  
Euysik Jeon
Keyword(s):  
Optimal Design ◽  
High Strength Steel ◽  
Design Method ◽  
High Strength ◽  
Optimization Method ◽  
Design Criterion ◽  
Thickness Optimization ◽  
Element Analysis ◽  
Strength Design ◽  
Seat Frame

In this paper, the authors proposed an optimal design method for the strength design of infant pop-up seat frame combined with rear seats for infants, children, and adults, not removable booster seats or car seats. Frame strength design was performed using discrete material and thickness optimization (DMTO) method considering high strength steel (HSS) and advanced high strength steel (AHSS). Structural design using the Section 4 link mechanism was performed, and the weakness of the seat frame due to static load was confirmed through finite element analysis. An optimal design criterion was established by carrying out a case study to derive the limiting conditions according to static and dynamic loads. In consideration of these criteria, the optimal design according to d-optimal and discrete Latin-hypercube (DLH) was performed among the design of experiments (DOE). And the strength of the pop-up seat frame for infants according to each DOE was checked, and the strength optimization method was suggested by comparing the lightweight ratio.

Design of a small disc-type coreless permanent magnet brushed DC actuator

2021 ◽  
Vol 40 (5) ◽  
pp. 997-1010
Author(s):  
Mohammad Reza Alizadeh Pahlavani ◽  
Hamed Tahanian
Keyword(s):  
Permanent Magnet ◽  
Design Method ◽  
Experimental Tests ◽  
Element Analysis ◽  
Content Type ◽  
Dc Motors ◽  
Design Variables ◽  
Small Disc ◽  
In Series ◽  
Slip Rings

Purpose Design of small disc-type permanent magnet (PM) brushed DC motors for servomechanisms is challenging. The purpose of this paper is to propose a special coreless double-sided structure. This easy to manufacture motor has two set of shifted concentrated windings on both sides of the rotor. All of the coils in each winding are simply connected in series. A simple arcless commutator, which shares the features of both the usual commutators and slip rings, is connected to each winding at only two points. Design/methodology/approach By replacing the PMs with an equivalent current density, main design equations of the motor have been derived through the solving of scalar Poisson equation. A radial division technique has been used to take the radial variations into account. This provides the ability of considering various shapes of coils and PMs. A novel iterative algorithm has been proposed to design a motor with high torque capability, compared to other coreless counterparts. Some design variables are obtained based on an independent optimization problem, which maximizes the active portion of windings. The other variables are calculated in such a way that the design requirements are satisfied. Findings The feasibility and capability of the new structure have been proved by prototyping a sample motor. Comparing the design outputs with the results of the 3D finite element analysis and experimental tests shows a good agreement. This verifies the accuracy of the proposed design method. Originality/value A new structure for PM brushed DC motors and a novel algorithm for its design has been developed.

Optimal design of spoke type motor and magnetizer using FEM and RSM

2018 ◽  
Vol 37 (2) ◽  
pp. 730-739
Author(s):  
Young Hyun Kim ◽  
Jung Ho Lee
Keyword(s):  
Optimal Design ◽  
Mass Production ◽  
Permanent Magnets ◽  
Design Method ◽  
Cost Effective ◽  
Torque Ripple ◽  
Efficient System ◽  
Cogging Torque ◽  
Content Type ◽  
Type Motor

PurposeThis study aims to propose criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration.Design/methodology/approachThe optimal design of the stator and rotor can be enhanced using both a response surface method (RSM) and finite element method (FEM). In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor.FindingsThe criteria not only improve performance but also reduce manufacturing costs. The criteria are verified FEM together with an RSM. These methods are used to optimize the stator and rotor shape and the magnetization system. These methods allow us to produce an efficient system for mass production of the motor.Originality/valueThis study proposed a design method that uses rare earth magnets in a system to replace the spoke-type IPM. To verify the optimal design, torque characteristics were analysed using FEM and RSM. Excellent results were achieved regarding the reduction of cogging torque and torque ripple. In addition, the design of the magnetizer enables a cost-effective mass production system for the motor.

Cost-Effective Method of Optimization of Stacking Sequences in the Cylindrical Composite Shells Using Genetic Algorithm

2020 ◽  
Author(s):  
Ehsan Daneshkhah ◽  
Reza Jafari Nedoushan ◽  
Davoud Shahgholian ◽  
Nima Sina
Keyword(s):  
Genetic Algorithm ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Tests ◽  
Cost Effective ◽  
Element Model ◽  
External Pressure ◽  
Element Analysis ◽  
Cost Effective Method ◽  
Critical Buckling Pressure

Buckling is one of the common destructive phenomena, which occurs in composite cylinders subjected to external pressure. In this paper, different methods to optimize stacking sequence of these cylinders are investigated. A finite element model is proposed in order to predict critical buckling pressure and the results are validated with previous experimental data. Theoretical analysis based on NASA SP‐8007 solution and the simplified equation for cylinder buckling of ASME RD-1172 are presented and discussed. The results of theoretical and finite element analysis and experimental tests are compared for both glass and carbon epoxy cylinders. Using NASA and ASME formulations, optimal laminations of cylinders in order to maximize buckling pressure, are obtained by genetic algorithm method. Suggested laminations and the values of corresponding critical buckling pressure calculated by finite element analysis, are presented and compared in various states. Obtained results show that while predicted buckling loads of finite element analysis are reliable, NASA formulation can be used in a very cost-effective method to optimize the buckling problems.

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