scholarly journals Numerical Optimization for the Impact Performance of a Rubber Ring Buffer of a Train Coupler

Machines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 225
Author(s):  
Ping Xu ◽  
Chengju Qu ◽  
Shuguang Yao ◽  
Chengxing Yang ◽  
Ao Wang
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Peak Force ◽  
Original Structure ◽  
Surface Model ◽  
Nsga Ii ◽  
Rubber Ring ◽  
Crushing Force ◽  
The Impact ◽  
Constitutive Parameters

Shock and vibration caused by mechanical motion bring huge potential threats to the service life and assembly reliability of mechanical systems. Rubber materials have been widely used in aircraft, trains, and other engineering fields, due to their excellent properties in shock and vibration absorption. This paper aimed to study the rubber ring buffer applied to a certain type of Chinese locomotive. Firstly, the finite element model was established and verified through experimental data. Based on the verified simulation model, the influence of the constitutive parameters (C01/C10 ratio height H and contour radius R) of the rubber ring on its energy absorption and peak crushing force under impact loading was studied in a numerical environment. Finally, the design of the experiment was carried out by the optimized Latin hypercube method, and the response surface model was established, which intuitively demonstrated the influence of the relevant parameters of the rubber ring on the change trend of the energy absorption and peak force. Based on the proxy model, the parameters that improve the crashworthiness of the rubber ring buffer were found quickly by the NSGA-II optimization algorithm, and the problems of a long calculation time and low optimization efficiency when using the conventional finite element method were avoided. The optimization results stated that when H = 107.57 mm and R = 85.70 mm, C01/C10 = 0.0571 of the energy absorption of the optimized buffer was increased by 59.03%, and the peak force was decreased by 14.37%, compared with the original structure. The optimized rubber ring buffer is expected to reduce the peak crushing force, enhance the energy absorption capacity, and mitigate the damage to the train system caused by shock and vibration.

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.

Computational Human Torso Model Validation for Frontal Blunt Trauma

2018 ◽  
Author(s):  
Carolyn E. Hampton ◽  
Michael Kleinberger
Keyword(s):  
Finite Element ◽  
Blunt Trauma ◽  
Energy Absorption ◽  
Elastic Material ◽  
Peak Force ◽  
Tissue Type ◽  
Absorption Data ◽  
Element Analysis ◽  
Material Models ◽  
Torso Model

Recent research on behind-armor blunt trauma (BABT) has focused on the personal protection offered by lightweight armor. A finite element analysis was performed to improve the biofidelity of the US Army Research Laboratory (ARL) human torso model to prepare for simulating blunt chest impacts and BABT. The overly stiff linear elastic material models for the torso were replaced with material characterizations drawn from current literature. FE torso biofidelity was determined by comparing peak force, force-compression, peak compression, and energy absorption data with cadaver responses to a 23.5 kg pendulum impacting at the sternum at 6.7 m/s. Nonlinear foam, viscous foam, soft rubbers, fibrous hyperelastic rubbers, and low moduli elastic material were considered as material models for the flesh, organs, and bones. Simulations modifying one tissue type revealed that the flesh characterization was most crucial for predicting compression and force, followed closely by the organs characterizations. Combining multiple tissue modifications allowed the FE torso to mimic the cadaveric torsos by reducing peak force and increasing chest compression and energy absorption. Limitations imposed by the Lagrangian finite element approach are discussed with potential workarounds described. Proposed future work is split between considering additional impact scenarios accounting for position and biomaterial variability.

Numerical and Experimental Investigation on the Energy Absorption Capability of a Full-Scale Composite Fuselage Section

2019 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Donato Perfetto ◽  
Giuseppe Lamanna ◽  
M. Manzo ◽  
A. Chiariello ◽  
F. di Caprio ◽  
...  
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Load Condition ◽  
Element Model ◽  
Full Scale ◽  
Research Centre ◽  
Fe Method ◽  
Explicit Finite Element ◽  
Crashworthiness Design ◽  
The Impact

In the case of catastrophic events, such as an emergency landing, the fuselage structure is demanded to absorb most of the impact energy preserving, at the same time, a survivable space for the passengers. Moreover, the increasing trend of using composites in the aerospace field is pushing the investigation on the passive safety capabilities of such structures in order to get compliance with regulations and crashworthiness requirements. This paper deals with the development of a numerical model, based on the explicit finite element (FE) method, aimed to investigate the energy absorption capability of a full-scale 95% composite made fuselage section of a civil aircraft. A vertical drop test, performed at the Italian Aerospace Research Centre (CIRA), carried out from a height of 14 feet so to achieve a ground contact velocity of 30 feet/s in according to the FAR/CS 25, has been used to assess the prediction capabilities of the developed FE method, allowing verifying the response under dynamic load condition and the energy absorption capabilities of the designed structure. An established finite element model could be used to define the reliable crashworthiness design strategy to improve the survival chance of the passengers in events such as the investigated one.

Impact Response of Circular Tube with Concentric Plunger

2013 ◽  
Vol 275-277 ◽  
pp. 792-798
Author(s):  
Amir Radzi Ab Ghani ◽  
Hafizi Lukman ◽  
Hafizan Hashim
Keyword(s):  
Energy Absorption ◽  
Circular Tube ◽  
High Energy ◽  
Absorption Capacity ◽  
Peak Force ◽  
Impact Response ◽  
Impact Performance ◽  
High Energy Absorption ◽  
The Impact ◽  
Initial Peak

Thin-walled tubes are generally used as impact energy absorber in various application due to their ease of fabrication and installation, high energy absorption capacity and long stroke. However, the main drawback of plain tube is the high initial peak force. A concentric plunger in the form of tapered block is proposed to overcome this shortcoming while at the same time, improving the impact performance. Static and dynamic axial crushing were performed to determine the initial peak force (IPF), crush force efficiency (CFE) and specific energy absorption (SEA) for the concentric plunger with various taper angles. It was found that the concentric plunger affected the tube impact response. Comparison with plain circular tube was carried out and it was found that the concentric plunger improved the impact response of the tube especially in term of initial peak force.

scholarly journals Variable Stiffness Design and Multiobjective Crashworthiness Optimization for Collision Post of Subway Cab Cars

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 246
Author(s):  
Wei Guo ◽  
Ping Xu ◽  
Zhaofeng Yi ◽  
Jie Xing ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Energy Absorption ◽  
Pareto Frontier ◽  
Variable Stiffness ◽  
Element Model ◽  
Surface Model ◽  
Front End ◽  
The Finite Element Model

This paper proposes a variable stiffness collision post (VSCP) structure based on a uniform stiffness collision post (USCP) structure and performs stiffness matching optimization for VSCPs. A collision post structure assembled in a subway front-end frame can maintain the living space and absorb a certain amount of the kinetic energy of an impact. The experiment was applied on USCP, and the finite element model was verified experimentally. To investigate the effects of the stiffness parameters of VSCP on the specific energy absorption response (SEA_VSCP) and the area of intrusion response (S_In), response surface models fitted from design of experiment were adopted with the finite element model. In addition, a multiobjective optimization design was realized by using the global response search method and a Pareto frontier sequence was generated, which was based on the developed response surface model. It was found that the optimal value of SEA_VSCP and S_In responses cannot be achieved at the same time. Finally, a grey relational analysis is propounded to attain a desirable balance between SEA_VSCP and S_In from the Pareto frontier sequence under constraints of the peak crash force of VSCP and energy absorption of the front-end of cab car. The optimization result shows that the crashworthiness of VSCP is better than that of USCP.

Axial Crushing of Thin-Walled Tubes With Kite-Shape Pattern

2015 ◽  
Author(s):  
Degao Hou ◽  
Yan Chen ◽  
Jiayao Ma ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Peak Force ◽  
Great Promise ◽  
Axial Crushing ◽  
Crushing Force ◽  
Collapse Mode ◽  
Shape Pattern ◽  
The Mean ◽  
Thin Walled ◽  
Initial Peak

Thin-walled tubes are widely used as energy absorption devices in automobiles, designed to protect the costly structures and people inside during an impact event through plastic deformation. They show excellent performance under axial loading in terms of weight efficiency, stroke distance and total energy absorption, but also have the disadvantage that the crushing force is not uniform during deformation process, especially with the existence of a high initial peak force. Recently, pattern design on tubular structures has received increasing attention. It has been found that, if the surface of a tube is pre-folded according to an origami pattern, the collapse mode of the tube can be altered, leading to changes in energy absorption performance. In this paper, we present a series of origami patterned tubes with a kite-shape pattern that is constructed by joining two pieces of Miura-ori. First of all, the geometry of the pattern is presented. We develop a theoretical model to predict the energy absorption associated with the axial crushing of the patterned tubes and derive a mathematical formula to calculate the mean crushing force accordingly. Secondly, a family of origami tubes with various profiles are designed, and their performances subjected to quasi-static axial crushing are numerically investigated. A parametric study is also conducted to establish the relationship between the pre-folded angle of the pattern and the initial peak force as well as the mean crushing force. Numerical results show that introducing patterns to thin-walled tubes offers three advantages in comparison with conventional tubes, i.e., a lower initial peak force, a more uniform crushing load, and a stable and repeatable collapse mode. A 36.0% increase in specific energy absorption and 67.2% reduction in initial peak force is achieved in the optimum case. The new origami patterned tubes show great promise as energy absorption devices.

scholarly journals Simulation of Low Velocity Impact on Composite Hemispherical Shell

2014 ◽  
Vol 564 ◽  
pp. 406-411
Author(s):  
Parnia Zakikhani ◽  
R. Zahari ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Experimental Testing ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
Hemispherical Shell ◽  
The Impact

Impact simulation with finite element analysis is an appropriate manner to reduce the cost and time taken to carry out an experimental testing on a component. In this study, the impact behavior of the composite hemispherical shell induced by low velocity impact is simulated in ABAQUS software with finite element method. To predict the responses of Kevlar fabric/polyester, glass fabric/polyester and carbon fabric/polyester in the form of a hemisphere, once as one layer and then as a three-layered composite under applied force by an anvil. The sequences of layers are changed, to investigate and compare the occurred alternations in the amount of energy absorption, impact force and specific energy absorption (SEA). The comparison of results showed that the highest and the lowest quantity of energy absorption and SEA belong to Carbon/Glass/Kevlar (CGK) and Kevlar/Carbon/Glass (KCG) respectively.

scholarly journals Finite Element Modelling Approach for Progressive Crushing of Composite Tubular Absorbers in LS-DYNA: Review and Findings

2021 ◽  
Vol 6 (1) ◽  
pp. 11
Author(s):  
Ali Rabiee ◽  
Hessam Ghasemnejad
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Low Cost ◽  
Peak Load ◽  
Experimental Studies ◽  
Single Layer ◽  
Element Model ◽  
Point Of View ◽  
Element Formulation ◽  
Crushing Force

Robust finite element models are utilised for their ability to predict simple to complex mechanical behaviour under certain conditions at a very low cost compared to experimental studies, as this reduces the need for physical prototypes while allowing for the optimisation of components. In this paper, various parameters in finite element techniques were reviewed to simulate the crushing behaviour of glass/epoxy tubes with different material models, mesh sizes, failure trigger mechanisms, element formulation, contact definitions, single and various numbers of shells and delamination modelling. Six different modelling approaches, namely, a single-layer approach and a multi-layer approach, were employed with 2, 3, 4, 6, and 12 shells. In experimental studies, 12 plies were used to fabricate a 3 mm wall thickness GFRP specimen, and the numerical results were compared with experimental data. This was achieved by carefully calibrating the values of certain parameters used in defining the above parameters to predict the behaviour and energy absorption response of the finite element model against initial failure peak load (stiffness) and the mean crushing force. In each case, the results were compared with each other, including experimental and computational costs. The decision was made from an engineering point of view, which means compromising accuracy for computational efficiency. The aim is to develop an FEM that can predict energy absorption capability with a higher level of accuracy, around 5% error, than the experimental studies.

Energy absorption characteristics of thin-walled steel tube filled with paper scraps

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5985-6002
Author(s):  
Peng Cheng ◽  
Qingchun Wang ◽  
Shi Ke
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Specific Energy ◽  
Steel Tube ◽  
Specific Energy Absorption ◽  
Crushing Force ◽  
Thin Walled Tube ◽  
The Mean ◽  
Thin Walled ◽  
Absorption Characteristics

The specific energy absorption of a thin-walled tube can be improved by filler. This study examined the potential use of a cheaper biomass filler, paper scraps, to enhance the energy absorption characteristics of the structure while reducing its cost, compared to that with a traditional filler such as foam material. Quasi-static crushing tests and finite element simulations were performed by using the explicit non-linear finite element software LS-DYNA to determine the improvements to the mean crushing force and specific energy absorption of the steel tube when filled with different densities of paper scraps. The mean crushing force and specific energy absorption of the empty tube, the paper scraps, and thin-walled tube filled with paper scraps were determined, and corresponding numerical simulations were performed. The simulation and test results showed that the impact performance of tube filled with paper scraps was greatly improved when paper scraps density was 0.35 g/cm3. By optimizing paper scraps filling structure, a new structure that could further enhance the specific energy absorption was obtained. The optimal scheme could increase the specific energy absorption of Q345 steel tube by 11.35%.

Non-Linear Analysis of Energy Absorption Systems Under Impact Loads Through FEM

2011 ◽  
Author(s):  
E. R. Ledesma-Orozco ◽  
J. A. Diosdado-De la Pen˜a ◽  
G. I. Pe´rez–Soto ◽  
A. Salazar-Garibay ◽  
J. F. Reveles-Arredondo ◽  
...  
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Linear Analysis ◽  
Finite Element Models ◽  
Impact Loads ◽  
Absorption System ◽  
Polystyrene Foam ◽  
Non Linear ◽  
The Impact ◽  
Bistable Structures

This paper presents the non-linear simulation of the impact on a structure with different energy absorption systems using finite element models. A comparison of the damage caused to the structure in case of impact without implementing energy absorption system, and implementing energy absorption systems based on bistable structures, polystyrene foam and aluminium foam are shown here in. The results demonstrate the advantages of using energy absorption systems on structures under impact loads.

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