Crashworthiness analysis and optimization of different configurations multi-layered corrugated sandwich panels under crush loading

2020 ◽  
pp. 109963622090975
Author(s):  
Chengfu Shu ◽  
Shujuan Hou ◽  
YX Zhang ◽  
Yutao Luo
Keyword(s):  
Experimental Design ◽  
Specific Energy ◽  
Sandwich Structure ◽  
Sandwich Panels ◽  
Functionally Graded ◽  
Orthogonal Experimental Design ◽  
Analysis Method ◽  
Range Analysis ◽  
Specific Energy Absorption ◽  
Graded Thickness

Multi-layered corrugated sandwich panels can be made up of different core shapes, different arrangements, the variable height, and variable thickness in every layer. In this paper, the crashworthiness behaviors of multi-layered corrugated sandwich panels with different configurations, which are controlled by these four factors, are analyzed and compared. The optimal configuration is found by adopting orthogonal experimental design and range analysis method. A novel multi-layered corrugated sandwich structure with functionally graded thickness is proposed and studied and is proved to better structural crashworthiness. First, finite element models of multi-layered corrugated sandwich panels are established and validated by experiment. Then, the effect of the four factors with three levels on crashworthiness is analyzed, and we obtain the main factor and the optimal configuration with the maximum specific energy absorption by using orthogonal experimental design and range analysis method. Finally, parametric studies and multi-objectives optimization of the proposed novel multi-layered corrugated sandwich structure with functionally graded thickness are conducted. The optimization is aimed at maximizing the specific energy absorption and minimizing the initial peak force under crush loading, based on the non-dominated sorting genetic algorithm and response surface method technique. These findings can provide valuable guidelines for the design of multi-layered corrugated sandwich panels with different configurations under crush loading.

Architected functionally graded porous lattice structures for optimized elastic-plastic behavior

2020 ◽  
Vol 234 (8) ◽  
pp. 1099-1116 ◽  
Author(s):  
Mahshid Mahbod ◽  
Masoud Asgari ◽  
Christian Mittelstedt
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Specific Energy ◽  
Elastic Moduli ◽  
Maximum Stress ◽  
Functionally Graded ◽  
Plastic Behavior ◽  
Lattice Structures ◽  
Porous Structures ◽  
Specific Energy Absorption

In this paper, the elastic–plastic mechanical properties of regular and functionally graded additively manufactured porous structures made by a double pyramid dodecahedron unit cell are investigated. The elastic moduli and also energy absorption are evaluated via finite element analysis. Experimental compression tests are performed which demonstrated the accuracy of numerical simulations. Next, single and multi-objective optimizations are performed in order to propose optimized structural designs. Surrogated models are developed for both elastic and plastic mechanical properties. The results show that elastic moduli and the plastic behavior of the lattice structures are considerably affected by the cell geometry and relative density of layers. Consequently, the optimization leads to a significantly better performance of both regular and functionally graded porous structures. The optimization of regular lattice structures leads to great improvement in both elastic and plastic properties. Specific energy absorption, maximum stress, and the elastic moduli in x- and y-directions are improved by 24%, 79%, 56%, and 9%, respectively, compared to the base model. In addition, in the functionally graded optimized models, specific energy absorption and normalized maximum stress are improved by 64% and 56%, respectively, in comparison with the base models.

Large deformation of corrugated sandwich panels under three-point bending

2020 ◽  
pp. 109963622092765 ◽  
Author(s):  
Fukun Xia ◽  
Yvonne Durandet ◽  
T X Yu ◽  
Dong Ruan
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Mechanical Response ◽  
Sandwich Panels ◽  
Deformation Mode ◽  
Theoretical Models ◽  
Peak Force ◽  
Specific Energy Absorption ◽  
Three Point Bending ◽  
Core Height

Corrugated sandwich panels are widely used in engineering applications for their excellent energy absorption and lightweight. In this research, the mechanical response of aluminum corrugated sandwich panels subjected to three-point bending is investigated experimentally, numerically, and theoretically. In the experiments, the sandwich panels were loaded under two conditions, namely base indentation and node indentation. A parametric study is conducted by ABAQUS/explicit to investigate the effects of geometric configurations (corrugation angle, core height, and core thickness) on the deformation mode, peak force, and energy absorption. Both peak force and specific energy absorption vary with the geometric parameters. Theoretical models are further developed to predict the force–displacement curves of the panels under the two loading conditions. The theoretically predicted crushing force is in good agreement with both the experimental and simulated results. Finally, the non-dominated sorting genetic algorithm II is adopted to optimize the geometric configuration to improve the specific energy absorption and reduce the weight of corrugated sandwich panels.

Effect of Alkali Treatment on the Quality of Hemp Fiber

2014 ◽  
Vol 9 (2) ◽  
pp. 155892501400900 ◽  
Author(s):  
Jie Zhang ◽  
Hua Zhang ◽  
Jianchun Zhang
Keyword(s):  
Chemical Composition ◽  
Experimental Design ◽  
Average Length ◽  
Alkali Treatment ◽  
Orthogonal Experimental Design ◽  
Average Weight ◽  
Range Analysis ◽  
Experimental Conditions ◽  
Hemp Fiber

An orthogonal experimental design was employed to study the effects of the bath ratio, time, and alkali dosage of alkali treatment on the chemical composition, fineness, average length, and staple rate of hemp fiber. Through normalization and average weight distribution of multiple indices, the quality of hemp fiber was quantified. Results of range analysis showed that the optimum quality of hemp fiber can be achieved under the following conditions: alkali treatment bath ratio, 1:10; time, 5 h; alkali dosage, 10 g/L; and length of hemp fiber, 16 mm to 29 mm. The reliability and repeatability of the best experimental conditions were further confirmed.

Application of Orthogonal Experimental Design on Reliability and Sensitivity Analysis

2011 ◽  
Vol 211-212 ◽  
pp. 651-655 ◽  
Author(s):  
Qin Shu He ◽  
Xi Nen Liu ◽  
Shi Fu Xiao
Keyword(s):  
Sensitivity Analysis ◽  
Experimental Design ◽  
Structural Parameters ◽  
Orthogonal Experimental Design ◽  
Random Input ◽  
Range Analysis ◽  
First Order ◽  
Reliability Method ◽  
Structural Responses ◽  
Input Variables

In the present paper, the effects of four structural parameters at three levels on the reliability and sensitivity of structure are investigated. Sensitivity of parameters is achieved by the range analysis and the significance of parameters is achieved by the variance analysis. A response surface based on orthogonal experimental design and finite element calculations is elaborated so that the relation between the random input variables and structural responses could be established. The First-Order Reliability Method (FORM) as an approximated method is used here to assess the reliability. Comparing with the results of Monte Carlo simulations by ANSYS for a numerical example, the effect of sensitivity analysis has been proved, while the precision of the reliability and sensitivity should be improved in the future.

Dynamic Axial Compression of Square CFRP/Aluminium Tubes

2019 ◽  
Vol 794 ◽  
pp. 202-207
Author(s):  
Rafea Dakhil Hussein ◽  
Dong Ruan ◽  
Guo Xing Lu ◽  
Jeong Whan Yoon ◽  
Zhan Yuan Gao
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Fibre Composite ◽  
Dynamic Tests ◽  
Carbon Fibre Composite ◽  
Specific Energy Absorption ◽  
Static Tests ◽  
Crushing Force ◽  
Cfrp Tubes ◽  
The Impact

Carbon fibre composite tubes have high strength to weight ratios and outstanding performance under axial crushing. In this paper, square CFRP tubes and aluminium sheet-wrapped CFRP tubes were impacted by a drop mass to investigate the effect of loading velocity on the energy absorption of CFRP/aluminium tubes. A comparison of the quasi-static and dynamic crushing behaviours of tubes was made in terms of deformation mode, peak crushing force, mean crushing force, energy absorption and specific energy absorption. The influence of the number of aluminium layers that wrapped square CFRP tubes on the crushing performance of tubes under axial impact was also examined. Experimental results manifested similar deformation modes of tubes in both quasi-static and dynamic tests. The dynamic peak crushing force was higher than the quasi-static counterpart, while mean crushing force, energy absorption and specific energy absorption were lower in dynamic tests than those in quasi-static tests. The mean crushing force and energy absorption decreased with the crushing velocity and increased with the number of aluminium layers. The impact stroke (when the force starts to drop) decreased with the number of aluminium layers.

Research on Process Parameter Optimization of the High-Neck Flange Closed Rolling Based on the Orthogonal Experimental Design

2014 ◽  
Vol 494-495 ◽  
pp. 461-465 ◽  
Author(s):  
Bao Shou Sun ◽  
Zhe Hong ◽  
Long Qing Xu ◽  
Xue Dao Shu ◽  
Bo Qin Gu ◽  
...  
Keyword(s):  
Experimental Design ◽  
Parameter Optimization ◽  
Rotational Speed ◽  
Rolling Process ◽  
Process Parameter ◽  
Orthogonal Experimental Design ◽  
Feed Speed ◽  
Initial Blank ◽  
Two Factors ◽  
Deform 3D

This paper simulates the process of the high-neck flange closed rolling on DEFORM-3D and optimizes the rolling process parameter by analyzing the results based on the orthogonal experimental design. For the high-neck flange, the results show that the effects on ellipticity are in the order of the mandrel feed speed, the main roll rotational speed and initial blank temperature. The former two factors show the significance while the initial blank temperature does not show that.

Design optimization of hopper cars employing functionally graded honeycomb sandwich panels

2021 ◽  
pp. 095440972110496
Author(s):  
Ayman Al-Sukhon ◽  
Mostafa SA ElSayed
Keyword(s):  
Design Optimization ◽  
Sandwich Panels ◽  
Design Procedure ◽  
Functionally Graded ◽  
Sandwich Composite ◽  
Wall Structure ◽  
Concentrate Mass ◽  
Cross Sectional ◽  
Baseline Design ◽  
Honeycomb Sandwich

In this paper, a novel multiscale and multi-stage structural design optimization procedure is developed for the weight minimization of hopper cars. The procedure is tested under various loading conditions according to guidelines established by regulatory bodies, as well as a novel load case that considers fluid-structure interaction by means of explicit finite elements employing Smoothed Particle Hydrodynamics. The first stage in the design procedure involves topology optimization whereby optimal beam locations are determined within the design space of the hopper car wall structure. This is followed by cross-sectional sizing of the frame to concentrate mass in critical regions of the hopper car. In the second stage, hexagonal honeycomb sandwich panels are considered in lower load regions, and are optimized by means of Multiscale Design Optimization (MSDO). The MSDO drew upon the Kreisselmeier–Steinhausser equations to calculate a penalized cost function for the mass and compliance of a hopper car Finite Element Model (FEM) at the mesoscale. For each iteration in the MSDO, the FEM was updated with homogenized sandwich composite properties according to four design variables of interest at the microscale. A cost penalty is summed with the base cost by comparing results of the FEM with the imposed constraints. Efficacy of the novel design methodology is compared according to a baseline design employing conventional materials. By invoking the proposed methodology in a case study, it is demonstrated that a mass savings as high as 16.36% can be yielded for a single hopper car, which translates into a reduction in greenhouse gas emissions of 13.09% per car based on available literature.

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