Experimental and numerical studies on failure and energy absorption of composite thin-walled square tubes under quasi-static compression loading

2020 ◽  
Vol 21 (6) ◽  
pp. 623-634
Author(s):  
Haolei Mou ◽  
Zhenyu Feng ◽  
Jiang Xie ◽  
Jun Zou ◽  
Kun Zhou
Keyword(s):  
Finite Element ◽  
Shell Model ◽  
Energy Absorption ◽  
Failure Mode ◽  
Failure Criterion ◽  
Finite Element Models ◽  
Static Compression ◽  
Compression Loading ◽  
Thin Walled ◽  
Simulation Results

AbstractTo analysis the failure and energy absorption of carbon fiber reinforced polymer (CFRP) thin-walled square tube, the quasi-static axial compression loading tests are conducted for [±45]3s square tube, and the square tube after test is scanned to further investigate the failure mechanism. Three different finite element models, i.e. single-layer shell model, multi-layer shell model and stacked shell mode, are developed by using the Puck 2000 matrix failure criterion and Yamada Sun fiber failure criterion, and three models are verified and compared according to the experimental energy absorption metrics. The experimental and simulation results show that the failure mode of [±45]3s square tube is the local buckling failure mode, and the energy are absorbed mainly by intralaminar and interlaminar delamination, fiber elastic deformation, fiber debonding and fracture, matrix deformation cracking and longitudinal crack propagation. Three different finite element models can reproduce the collapse behaviours of [±45]3s square tube to some extent, but the stacked shell model can better reproduce the failure mode, and the difference of specific energy absorption (SEA) is minimum, which shows the numerical simulation results are in better agreement with the test results.

The Influence of the Curved Transition on the Coach Roof Cross Beams in Rollover Crashworthiness

2011 ◽  
Vol 474-476 ◽  
pp. 1920-1925
Author(s):  
Fu Lin Shen ◽  
Jun Liang Jiu ◽  
Zhao Kai Li ◽  
Xu Liang Xie ◽  
Ying Hui Mao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Energy Absorption ◽  
Collision Energy ◽  
Element Model ◽  
Finite Element Models ◽  
Complete Vehicle ◽  
Simulation Results ◽  
Survival Space ◽  
Peak Value

In order to improve the rollover crashworthiness of coach, three roof beam structures commonly used in coach were established with finite element models for the rollover simulation, then the energy absorption, acceleration and body pillar deformation were analyzed. The simulation results show that circle-curved transition and non-curved transition on the roof have better collision performance. Especially, the latter not only reduces the acceleration peak value, but also transfers more collision energy to the offside lateral. The whole coach body will be involved in deformation, thus, the intrusion of survival space would be reduced. Finally, the complete vehicle skeleton finite element model of a 6127-type high-bed coach was built, and the influences of circle-curved transition and non-curved transition on the roof in rollover test were analyzed.

scholarly journals Energy Absorption Characteristics of a CFRP-Al Hybrid Thin-Walled Circular Tube under Axial Crushing

Aerospace ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 279
Author(s):  
Rongchao Jiang ◽  
Zongyang Gu ◽  
Tao Zhang ◽  
Dawei Liu ◽  
Haixia Sun ◽  
...  
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Circular Tube ◽  
Finite Element Models ◽  
Axial Crushing ◽  
Circular Tubes ◽  
Absorption Performance ◽  
Thin Walled ◽  
Entropy Weighted ◽  
Absorption Characteristics

Thin-walled tubes have gained wide applications in aerospace, automobile and other engineering fields due to their excellent energy absorption and lightweight properties. In this study, a novel method of entropy-weighted TOPSIS was adopted to study the energy absorption characteristics of a thin-walled circular tube under axial crushing. Three types of thin-walled circular tubes, namely, aluminum (Al) tubes, carbon-fiber-reinforced plastics (CFRP) tubes and CFRP-Al hybrid thin-walled tubes, were fabricated. Quasi-static axial crushing tests were then carried out for these specimens, and their failure modes and energy absorption performance were analyzed. The CFRP material parameters were obtained through tensile, compression and in-plane shear tests of CFRP laminates. The finite element models for the quasi-static axial crushing of these three types of circular tubes were established. The accuracy of the finite element models was verified by comparing the simulation results with the test results. On this basis, the effects of the geometric dimension and ply parameters of a CFRP-Al hybrid thin-walled circular tube on the axial crushing energy absorption characteristics were studied based on an orthogonal design and entropy-weighted TOPSIS method. The results showed that Al tube thickness, CFRP ply thickness and orientation have great effect on the energy absorption performance of a CFRP-Al hybrid thin-walled circular tube, whereas the tube diameter and length have little effect. The energy absorption capability of a CFRP-Al hybrid tube can be improved by increasing the thickness of the Al tube and the CFRP tube as well as the number of ±45° plies.

Compressive Strength Analysis of MWD Microchip Tracer

2014 ◽  
Vol 511-512 ◽  
pp. 561-564
Author(s):  
Ji Bo Li ◽  
Wei Ning Ni ◽  
San Guo Li ◽  
Zu Yang Zhu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compressive Strength ◽  
Working Conditions ◽  
Failure Criterion ◽  
Strength Analysis ◽  
Design Phase ◽  
Key Issues ◽  
Simulation Results ◽  
Better Than

Pressure resistant performance of Measure While Drilling (MWD) microchip tracer to withstand the harsh downhole environment is one of the key issues of normal working. Therefore, it is an effective way to analyze pressure resistant performance of the tracer in the design phase. Compressive strength of the tracer was studied based on finite element method. Considering downhole complexity and working conditions during the processing of tracer roundness, material non-uniformity and other factors. In this study, researchers took sub-proportion failure criterion to determine the failure of tracer. Simulation results of two structures, with pin and without pin, show that both structures met the requirement of downhole compressive strength, and the structure with pin was better than the structure without pin. This study provides basis for downhole application of microchip tracers.

scholarly journals Reconstruction finite element model of cars

2021 ◽  
Vol 4 (1) ◽  
pp. first
Author(s):  
Lý Hùng Anh ◽  
Nguyễn Phụ Thượng Lưu ◽  
Nguyễn Thiên Phú ◽  
Trần Đình Nhật
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Finite Element Models ◽  
Crash Analysis ◽  
Inertia Moment ◽  
Frontal Crash ◽  
Analysis Center ◽  
Simulation Results ◽  
And Behavior

The experimental method used in a frontal crash of cars costs much time and expense. Therefore, numerical simulation in crashworthiness is widely applied in the world. The completed car models contain a lot of parts which provided complicated structure, especially the rear of car models do not contribute to behavior of frontal crash which usually evaluates injuries of pedestrian or motorcyclist. In order to save time and resources, a simplification of the car models for research simulations is essential with the goal of reducing approximately 50% of car model elements and nodes. This study aims to construct the finite element models of front structures of vehicle based on the original finite element models. Those new car models must be maintained important values such as mass and center of gravity position. By using condition boundaries, inertia moment is kept unchanged on new model. The original car models, which are provided by the National Crash Analysis Center (NCAC), validated by using results from experimental crash tests. The modified (simplistic) vehicle FE models are validated by comparing simulation results with experimental data and simulation results of the original vehicle finite element models. LS-Dyna software provides convenient tools and very strong to modify finite element model. There are six car models reconstructed in this research, including 1 Pick-up, 2 SUV and 3 Sedan. Because car models were not the main object to evaluate in a crash, energy and behavior of frontal part have the most important role. As a result, six simplified car models gave reasonable outcomes and reduced significantly the number of nodes and elements. Therefore, the simulation time is also reduced a lot. Simplified car models can be applied to the upcoming frontal simulations.

scholarly journals The method of direct finite perturbation of numerical models for studying of the dynamic, stiffness and strength properties for thin-walled elements of engineering constructions.

2014 ◽  
Vol 2014 (4) ◽  
pp. 114-124
Author(s):  
Юрий Костенко ◽  
Yuriy Kostenko ◽  
Анатолий Чепурной ◽  
Anatoliy Chepurnoy ◽  
Александр Литвиненко ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Natural Frequencies ◽  
Numerical Models ◽  
Dynamic Stiffness ◽  
Strength Properties ◽  
Test Problems ◽  
Finite Element Models ◽  
Direct Perturbation ◽  
Thin Walled

The methods of direct perturbation for finite element models of thin-walled engineering constructions for sensitivity analysis of their strength, stiffness and dynamic characteristics to the change in their thickness are proposed. The approach for prediction of distribution for natural frequencies migration as result of change in their thickness are presented. The applicability of the linearized models to determine displacements, stresses and natural frequencies slightly thinned design compared to the nominal (original) are shown. The examples of test problems are given.

scholarly journals Increasing Damping of Thin-Walled Structures Using Additively Manufactured Vibration Eliminators

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2125 ◽  
Author(s):  
Paweł Dunaj ◽  
Stefan Berczyński ◽  
Karol Miądlicki ◽  
Izabela Irska ◽  
Beata Niesterowicz
Keyword(s):  
Finite Element ◽  
Dynamic Stiffness ◽  
Experimental Studies ◽  
Steel Beam ◽  
Finite Element Models ◽  
Fem Model ◽  
Thin Walled Structures ◽  
Resonance Frequencies ◽  
Thin Walled ◽  
Parametric Analyses

The paper presents a new way to conduct passive elimination of vibrations consisting of covering elements of structures with low dynamic stiffness with polylactide (PLA). The PLA cover was created in 3D printing technology. The PLA cover was connected with the structure by means of a press connection. Appropriate arrangement of the PLA cover allows us to significantly increase the dissipation properties of the structure. The paper presents parametric analyses of the influence of the thickness of the cover and its distribution on the increase of the dissipation properties of the structure. Both analyses were carried out using finite element models (FEM). The effectiveness of the proposed method of increasing damping and the accuracy of the developed FEM models was verified by experimental studies. As a result, it has been proven that the developed FEM model of a free-free steel beam covered with polylactide enables the mapping of resonance frequencies at a level not exceeding 0.6% of relative error. Therefore, on its basis, it is possible to determine the parameters of the PLA cover. Comparing a free-free steel beam without cover with its PLA-covered counterpart, a reduction in the amplitude levels of the receptance function was achieved by up to 90%. The solution was validated for a steel frame for which a 37% decrease in the amplitude of the receptance function was obtained.

scholarly journals The Effect of Swinging Ball Heads with Different Arrangements in Multi-Point Stretch-Forming Process

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 337 ◽  
Author(s):  
Jian Xing ◽  
Yan-yan Cheng ◽  
Zhuo Yi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Sheet Metal ◽  
Strain Distribution ◽  
Finite Element Models ◽  
Stretch Forming ◽  
Forming Process ◽  
Forming Quality ◽  
Staggered Arrangement ◽  
Simulation Results

To improve the effect of multi-point stretch forming of sheet metal, it is proposed in this paper to replace a fixed ball head with a swinging ball head. According to the multi-point dies with different arrangements, this research establishes finite element models of the following stretch forming, i.e., fixed ball heads with conventional arrangement, swinging ball heads with conventional arrangement, swinging ball heads with declining staggered arrangement, and swinging ball heads with parallel staggered arrangement, and then numerical simulation is performed. The simulation results show that by replacing a fixed ball head with a swinging ball head, the surface indentation of the part formed was effectively suppressed, the stress and tension strain distribution of the part formed was improved, and the forming quality was improved; the thickness of the elastic pad was reduced, the springback was reduced and the forming accuracy was improved; and when the ball head was applied to a multi-point die with staggered arrangement, a better forming result was achieved, where the best forming result was achieved in combining the swinging ball heads with the multi-point die with a parallel staggered arrangement. Forming experiments were carried out, and the experimental results were consistent with the trend of numerical simulation results, which verified the correctness of the numerical simulation.

Study the Influence of Geometric Parameters on Springback in T-Section Aluminum Alloy Window Trim Strip Sheets Forming

2018 ◽  
Vol 920 ◽  
pp. 70-76 ◽  
Author(s):  
Bao Hang Zhu ◽  
Yi Xi Zhao ◽  
Zhong Qi Yu ◽  
Hui Yan
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Geometric Parameters ◽  
Finite Element Models ◽  
Quality Requirement ◽  
Forming Process ◽  
Assembly Quality ◽  
Simulation Results ◽  
In The Beginning ◽  
Springback Control

The T-section aluminum alloy window trim strip sheets are used to improve vehicle appearance. As the mobile scenery line, these window trim strips with claws need high forming accuracy to meet good assembly quality requirement. The top portion of the T-section sheet is stamped to form an edge flange structure. Springback control is essential in forming process. In this paper, the influence of the window trim strip geometric parameters on forming springback is studied. Some finite element models of the process were built with the Dynaform software. The simulation results were verified experimentally. The main conclusions include as belows: The different heights of the stiffeners part in T-section change the stiffness of the part. Although the stiffeners part does not participate in the forming, it also has springback in the forming process. So, it is necessary to study the influence of the flanging part width (W) and the stiffeners part height (H) of the T-section on springback. We set W to 15 mm and change the value of H value according to the real product. The value of springback increases with the increase of H value in the beginning. After ratio of H/W increases to 0.6, the value of springback fluctuates with the increase of H value. When ratio of H/W is about 0.5, the springback values are mostly less than ± 0.5 mm in key sections, which is acceptable.

Optimal Clamping Scheme of Thin-Walled Cavity Workpiece

2011 ◽  
Vol 189-193 ◽  
pp. 2116-2120
Author(s):  
Shi Min Geng ◽  
Jun Wang
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Machining Process ◽  
Machining Accuracy ◽  
Finite Element Models ◽  
Thin Walled ◽  
Clamping Sequence

The thin-walled cavity workpiece with insufficient rigid property is liable to deform during the machining process and the request of accuracy is very strict. The paper takes typical aeronautic aluminum-alloy for example, fixture is an important consideration in the operation. To reveal the influences of locating points, clamping sequence and loading ways on the distortion of thin-walled cavity part, finite element models were established to simulate the clamping operation. The result shows the preferable scheme is that the distance of the clamping locations are far each other, clamping forces are firstly applied on the surface with high rigid and all clamping forces are applied in many steps. The scheme can effectively control the deformation of clamp ,and furthermore improve the machining accuracy.

Harmonic Wave Propagation of Ultrasonic Arc Stators

Aerospace ◽  
2003 ◽  
Author(s):  
P. Smithmaitrie ◽  
J. G. DeHaven ◽  
K. Higuchi ◽  
H. S. Tzou
Keyword(s):  
Finite Element ◽  
Traveling Waves ◽  
Traveling Wave ◽  
Harmonic Wave ◽  
Finite Element Models ◽  
Governing Equations ◽  
Modeling And Analysis ◽  
Element Simulation ◽  
Simulation Results ◽  
Harmonic Analyses

A piezoelectric curvilinear arc stator designed for an ultrasonic curvilinear motor is studied in this research. Design of piezoelectric curvilinear arc stator is proposed and its governing equations and vibration behavior are investigated. Then, analysis of forced vibration response or driving characteristics to harmonic excitations in the modal domain is conducted. Finite element modeling and analysis of the arc stator are also discussed. Analytical results of free vibration characteristics are compared favorably with the finite element results. Harmonic analyses of the three finite element models reveal changes of dynamic behaviors of three models and also imply operating frequencies with significant traveling wave component. Study of mathematical and finite element simulation results suggests that stable traveling waves can be generated to drive a motor on the proposed curvilinear arc stator system.

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