EFFECT OF RELATIVE DENSITY AND VELOCITY TOWARDS DYNAMIC RESPONSE OF METAL FOAM

2015 ◽  
Vol 76 (9) ◽  
Author(s):  
Mohd Azman Y. ◽  
Juri S. ◽  
Hazran H. ◽  
NorHafiez M. N. ◽  
Dong R.
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Theoretical Prediction ◽  
Relative Density ◽  
Impact Velocity ◽  
Impact Test ◽  
Metal Foam ◽  
Element Analysis ◽  
Static Tests ◽  
The Impact

Dynamic response of ALPORAS aluminium foam has been investigated experimentally and numerically. The dynamic response is quantified by the force produced as the foam deforms as a function of time. Quasi-static tests are conducted to determine the quasi-static properties of the foam. In the impact test, the aluminium foams are fired towards a rigid load-cell and the force signals developed are recorded. Experimental dynamic stress is also compared with theoretical prediction using existing theory. Finite element model is constructed using LS-DYNA to simulate the impact test. Results from the experiment, finite element analysis and theoretical prediction are in acceptable agreement. Finally, parametric studies have been conducted using the verified model to investigate the effect of impact velocity and relative density towards the dynamic response of the foam projectile. It is found that the dynamic response of the foam is more sensitive towards impact velocity as compare with the foam relative density.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

scholarly journals Finite Element Analysis of Impact Energy on Spur Gear

2018 ◽  
Vol 225 ◽  
pp. 06011 ◽  
Author(s):  
Ismail Ali Bin Abdul Aziz ◽  
Daing Mohamad Nafiz Bin Daing Idris ◽  
Mohd Hasnun Arif Bin Hassan ◽  
Mohamad Firdaus Bin Basrawi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Energy ◽  
High Speed ◽  
Impact Test ◽  
Impact Load ◽  
Gear Tooth ◽  
Test Equipment ◽  
Element Analysis ◽  
The Impact

In high-speed gear drive and power transmission, system impact failure mode always occurs due to the sudden impact and shock loading during the system in running. Therefore, study on the amount of impact energy that can be absorbed by a gear is vital. Impact test equipment has been designed and modelled for the purpose to study the impact energy on gear tooth. This paper mainly focused on Finite Element Analysis (FEA) of impact energy that occurred during simulation involving the impact test equipment modelling. The simulation was conducted using Abaqus software on critical parts of the test equipment to simulate the impact event and generate impact data for analysis. The load cell in the model was assumed to be free fall at a certain height which gives impact load to the test gear. Three different type of material for the test gear were set up in this simulation. Results from the simulation show that each material possesses different impact energy characteristic. Impact energy values increased along with the height of load drop. AISI 1040 were found to be the toughest material at 3.0m drop that could withstand up to 44.87N.m of impact energy. These data will be used to validate data in physical experiments in further study.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Impact Load ◽  
Residual Deformation ◽  
Time History ◽  
Single Layer ◽  
Element Analysis ◽  
Deformation Stage ◽  
The Impact

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

Agricultural aircraft wing slat tolerance for bird strike

2017 ◽  
Vol 89 (4) ◽  
pp. 590-598 ◽  
Author(s):  
Adam Deskiewicz ◽  
Rafał Perz
Keyword(s):  
Finite Element ◽  
Impact Velocity ◽  
Structural Response ◽  
Element Model ◽  
Bird Strike ◽  
Element Analysis ◽  
Content Type ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
The Impact

Purpose The aim of this study is to assess and describe possible consequences of a bird strike on a Polish-designed PZL-106 Kruk agricultural aircraft. Due to its susceptibility to such events, a wing slat has been chosen for analysis. Design/methodology/approach Smooth particle hydrodynamics (SPH) formulation has been used for generation of the bird finite element model. The simulations were performed by the LS-Dyna explicit finite element analysis software. Several test cases have been analysed with differing parameters such as impact velocity, initial velocity vector direction, place of impact and bird mass. Findings Results of this study reveal that the structure remains safe after an impact at the velocity of 25 m/s. The influence of bird mass on slat damage is clearly observable when the impact velocity rises to 60 m/s. Another important finding was that in each case where the part did not withstand the applied load, it was the lug where first failure occurred. Some of the analysed cases indicated the possibility a consequent wing box damage. Practical implications This finding provides the manufacturer an important insight into the behaviour of the slat and suggests that more detailed analysis of the current lug design might improve the safety of the structure. Originality/value Even though similar analyses have been performed, they tended to focus on large transport aircraft components. This investigation will enhance our understanding of structural response of small, low-speed aircraft to a bird impact, which is a realistic scenario for the chosen case of an agricultural plane.

Parametric Study of Low Velocity Impact Using Finite Element Analysis

2013 ◽  
Vol 393 ◽  
pp. 397-402 ◽  
Author(s):  
Mohd Ridhuan Mohd Sahri ◽  
Che Muhamad Khairul Iezuadi Che Muhamad ◽  
Mohd Juzaila Abd Latif ◽  
Jamaluddin Mahmud
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Impact Velocity ◽  
Equivalent Plastic Strain ◽  
Low Velocity Impact ◽  
Skin Thickness ◽  
Low Velocity ◽  
Element Analysis ◽  
Material Response ◽  
The Impact

An aircraft structural and material response is very complex when subjected to impact. It involves both elastic and plastic deformation in instant. Nevertheless, investigating this phenomenon is challenging yet interesting. Therefore, this research attempts to investigate the effect of selected parameters variation (i.e. material type, skin thickness and impact velocity) to the resulting equivalent plastic shear strain using finite element analysis (FEA). The finite element (FE) models were developed using commercially modeling and FE software to replicate an aircraft fuselage (target) and projectile according to the experimental setup and data established by other researcher [. The current study only focuses on the materials response and deformation behavior due low velocity (30 150 m/s) impact of a blunt object to a square shape target made of Al 2024-T3 and aluminum alloy 7475 (AA 7475). In all cases (parameters variation), the resulting equivalent plastic strain has been determined and compared to the established data. It is found that the currents results are very close to the actual material response measured in experiments. This proves that simulated results are validated and the study contributed some knowledge to understanding the behaviour of the structural and material response in a low impact velocity. By varying selected parameters, the impact resistivity of the structure could be improved.

Impact Behavior Analysis of PC/ABS (50/50) Blends

2005 ◽  
Vol 297-300 ◽  
pp. 1297-1302 ◽  
Author(s):  
M. Nizar Machmud ◽  
Masaki Omiya ◽  
Hirotsugu Inoue ◽  
Kikuo Kishimoto
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Impact Test ◽  
Large Strain ◽  
Rubber Particle ◽  
Particle Diameter ◽  
Polymeric Materials ◽  
Impact Behavior ◽  
Element Analysis ◽  
The Impact

Impact behavior of simply-supported circular thin plates made of PC/ABS (50/50) blends tested at room temperature by use of instrumented drop weight impact apparatus under different speeds: 2, 3, and 4m/sec has been studied. The blends have 10wt% content of rubber with rubber particle diameter of 270nm and of 150-170nm distributed in ABS. Features of the target are viewed to describe definite alteration of the plates induced by a hemispherical tip-ended cylindrical impactor and effect of rubber particle size distributed in the blends. It was found that the blends with a rubber particle diameter of 150-170nm were not in shattering and exhibited a unique crack shape at speed of 3m/sec. Simulation of the impact test was also performed using dynamic explicit finite element code of MSC. Dytran. In the simulation, the material was assumed isotropic and mass served as a rigid surface and an available material model in the finite element system, called piecewise linear plasticity, referring to a yield model of the von Mises was applied in the simulation for describing the large strain, non-linear behavior of the polymeric materials. Maximum plastic strain failure criterion was then used to simulate the impact failure. Contact between the impactor and the plate was applied and friction coefficient µ between the impactor and the plate was neglected. In order to study effect of friction coefficient value, additional simulation of the impact test has also been performed using µ = 0.3. Impact force-time histories of the blends obtained from the simulation were then verified to the impact test results and pointed out an evaluation of the use of the finite element analysis for predicting behavior of the blends under the impact loading.

scholarly journals Deflection calculation of cam profile due to a Hertzian contact pressure

2020 ◽  
Vol 37 ◽  
pp. 149-160
Author(s):  
Louay S Yousuf
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Response ◽  
Contact Pressure ◽  
Reduction Rate ◽  
Hertzian Contact ◽  
Element Analysis ◽  
Cam Profile ◽  
The Impact ◽  
Contact Parameters

Abstract The bending deflection of cam profile was analyzed for three paths of contact and distinct Hertzian contact pressure. The impact happened between the disc cam and roller follower based on the contact parameters. The contact parameters are contact body stiffness, sliding contact velocity, exponent and penetration. A disc cam and roller follower system were discussed and analyzed for the dynamic response of the follower and bending deflection of the cam profile. The objective of this paper was to study the effect of contact load on the bending deflection. A system with spring stiffness (k) and viscous damping coefficient (c) at the end of the follower stem was used to reduce the bending deflection on the cam profile. The theory of circular plate was applied to derive the analytic solution of the bending deflection. The dynamic response of the follower had been determined by using the SolidWorks software based on the contact parameters. The experimental setup was done through an infrared camera device. Finite-element analysis was used to calculate the bending deflection of the cam profile numerically. Finite-element analysis was carried out by using the ANSYS version 19.2 package. The analytic and simulation results are checked and verified for bending deflection at the point of contact. The reduction rate for bending deflection was 73.425% for path no. (1), 85.925% for path no. (2) and 61.467% for path no. (3).

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

scholarly journals Thermo-responsive and shape-morphing CF/GF composite skin: Full-field experimental measurement, theoretical prediction, and finite element analysis

2021 ◽  
Vol 160 ◽  
pp. 106874
Author(s):  
Jamal Seyyed Monfared Zanjani ◽  
Pouya Yousefi Louyeh ◽  
Isa Emami Tabrizi ◽  
Abdulrahman Saeed Al-Nadhari ◽  
Mehmet Yildiz
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Theoretical Prediction ◽  
Experimental Measurement ◽  
Element Analysis ◽  
Full Field ◽  
Shape Morphing

Geometrically nonlinear static and dynamic analysis of CNT reinforced laminated composite plates: A finite element study

2021 ◽  
pp. 095440622110089
Author(s):  
Balakrishna Adhikari ◽  
BN Singh
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Dynamic Response ◽  
Integration Scheme ◽  
Static And Dynamic Analysis ◽  
Finite Element Study ◽  
Nonlinear Eigenvalues ◽  
Nonlinear Static ◽  
The Impact ◽  
Element Study

In this paper, a finite element study is conducted using the Green Lagrange strain field based on vonKarman assumptions for the geometric nonlinear static and dynamic response of the laminated functionally graded CNT reinforced (FG-CNTRC) composite plate. The governing equations for determining the nonlinear static and dynamic behavior of the FG-CNTRC plate are derived using the Lagrange equation of motion based on Reddy's higher order theory. Using the direct iteration technique, the nonlinear eigenvalues for analyzing the free vibration response are obtained and the nonlinear dynamic responses of the FG-CNTRC plate are encapsulated based on the nonlinear Newmark integration scheme. The impact of the amplitude of vibration on mode switching phenomena and the consequence of the duration of the pulse on the free vibration regime of the plate are outlined. Also, the effect of time dependent loads is studied on the normal stresses of the plate. Furthermore, the impact on the nonlinear static and dynamic response of the laminated FG-CNTRC plate of various parameters such as span-thickness ratio (b/h ratio), aspect ratio (a/b ratio), different edge constraints, CNT fiber gradation, etc. are also studied.

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