Experimental and Numerical Plastic Response and Failure of Laterally Impacted Rectangular Plates

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
B. Liu ◽  
R. Villavicencio ◽  
C. Guedes Soares
Keyword(s):  
Finite Element ◽  
Numerical Simulations ◽  
Failure Modes ◽  
Mesh Size ◽  
Plastic Behavior ◽  
Finite Element Models ◽  
Rectangular Plates ◽  
Marine Structures ◽  
Fine Mesh ◽  
The Impact

Experimental and numerical results of drop weight impact test are presented on the plastic behavior and fracture of rectangular plates stuck laterally by a mass with a hemispherical indenter. Six specimens were tested in order to study the influence of the impact velocity and the diameter of the indenter. The impact scenarios could represent abnormal actions on marine structures, such as ship collision and grounding or dropped objects on deck structures. The tests are conducted on a fully instrumented impact tester machine. The obtained force-displacement response is compared with numerical simulations, performed by the LS-DYNA finite element solver. The simulations aim at proposing techniques for defining the material and restraints on finite element models which analyze the crashworthiness of marine structures. The mesh size and the critical failure strain are predicted by numerical simulations of the tensile tests used to obtain the mechanical properties of the material. The experimental boundary conditions are modeled in order to represent the reacting forces developed during the impact. The results show that the critical impact energy until failure is strongly sensitive to the diameter of the striker. The shape of the failure modes is well predicted by the finite element models when a relatively fine mesh is used. Comments on the process of initiation and propagation of fracture are presented.

Experimental and Numerical Plastic Response and Failure of Laterally Impacted Rectangular Plates

2012 ◽  
Author(s):  
Bin Liu ◽  
Richard Villavicencio ◽  
C. Guedes Soares
Keyword(s):  
Finite Element ◽  
Numerical Simulations ◽  
Failure Modes ◽  
Mesh Size ◽  
Tensile Tests ◽  
Finite Element Models ◽  
Rectangular Plates ◽  
Marine Structures ◽  
Fine Mesh ◽  
The Impact

Experimental and numerical results of drop weight impact test are presented, on the plastic behaviour and fracture of rectangular plates stuck laterally by a mass with a hemispherical indenter. Six specimens were tested in order to study the influence of the impact velocity and the diameter of the indenter. The impact scenarios could represent abnormal actions on marine structures, such as ship collision and grounding or dropped objects on deck structures. The tests are conducted on a fully instrumented impact tester machine. The obtained force-displacement response is compared with numerical simulations, performed by the LS-DYNA finite element solver. The simulations aim at proposing techniques for defining the material and restraints on finite element models which analyze the crashworthiness of marine structures. The mesh size and the critical failure strain are predicted by numerical simulations of the tensile tests used to obtain the mechanical properties of the material. The experimental boundary conditions are modelled in order to represent the reacting forces developed during the impact. The results show that the critical impact energy until failure is strongly sensitive to the diameter of the striker. The shape of the failure modes is well predicted by the finite element models when a relatively fine mesh is used. Comments on the process of initiation and propagation of fracture are presented.

Influence of Impact Location on the Plastic Response and Failure of Rectangular Cross Section Tubes Struck Transversely by a Hemispherical Indenter1

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Bin Liu ◽  
C. Guedes Soares
Keyword(s):  
Numerical Simulations ◽  
Cross Section ◽  
Failure Modes ◽  
Rectangular Cross Section ◽  
Plastic Behavior ◽  
Collapse Mechanism ◽  
Transverse Loads ◽  
Impact Location ◽  
The Impact ◽  
Rectangular Tubes

Drop weight impact tests and numerical simulations have been performed to examine the plastic behavior and failure of clamped rectangular cross section tubes subjected to transverse loads. The selected indenter is a hemisphere with diameter of 20 mm. The tube lengths are 125 and 250 mm, and they are struck at the midspan and the quarter-span. The impact point along the width direction is located at the central position and displaced 10 mm from the center, respectively. The results show that the impact location affects strongly the plastic behavior and failure of the tubes. The impact location displaced along the width increases the energy absorbing capability of the tubes accompanied with an asymmetrical deformation mode. The experimentally recorded force–displacement responses and failure modes show good agreement with the numerical simulations, performed by the LS-DYNA finite-element code. The numerical results show the process of crack initiation and propagation and provide the details to analyze the structural plastic deformation and failure of the tubular specimens under transverse loads. The impact characteristics of the rectangular tubes are well presented based on the relevant failure modes observed in beams, plates, and circular tubes. Moreover, the influence of the impact location on the strength of tube specimens is characterized, and the collapse mechanism of rectangular tubes is described.

Behavior of Structures Using Simple Plastic Hinge Theory

1994 ◽  
Author(s):  
Ramakrishnan Maruthayappan ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cantilever Beam ◽  
Reliable Method ◽  
Plastic Hinge ◽  
Element Model ◽  
Finite Element Models ◽  
Computational Program ◽  
Hinge Model ◽  
The Impact

Abstract The behavior of structures under the impact or crash situations demands an efficient modeling of the system for its behavior to be predicted close to practical situations. The various formulations that are possible to model such systems are spring mass models, finite element models and plastic hinge models. Of these three techniques, the plastic hinge theory offers a more accurate model compared to the spring mass formulation and is much simpler than the finite element models. Therefore, it is desired to model the structure using plastic hinges and to use a computational program to predict the behavior of structures. In this paper, the behavior of some simple structures, ranging from an elementary cantilever beam to a torque box are predicted. It is also shown that the plastic hinge theory is a reliable method by comparing the results obtained from a plastic hinge model of an aviation seat structure with that obtained from a finite element model.

Influence of Basic Parameters for Fiber Reinforced Polymer Crushing Simulation

2016 ◽  
Author(s):  
Benoit Stalin ◽  
Dongyang Yang ◽  
Yong Xia ◽  
Qing Zhou
Keyword(s):  
Finite Element ◽  
Mesh Size ◽  
Fiber Reinforced Polymer ◽  
Physical Parameters ◽  
Large Element ◽  
Fiber Reinforced ◽  
Time Step ◽  
Reinforced Polymer ◽  
Simulation Results ◽  
The Impact

This article investigates the influence of finite element model features on Fiber Reinforced Polymer (FRP) crushing simulation results. The study focuses on two composite material tube models using single shell modeling approach. The chosen material model is MAT58 (*MAT_LAMINATED_COMPOSITE_FABRIC) from the commercial finite element analysis software LS-Dyna. The baseline models geometry and material parameters come from a model calibration conducted for lightweight vehicle investigation. Five parameters are investigated. The mesh size and the number of integration point (NIP) are generic and ERODS, TSIZE and SOFT are the non-physical parameters of MAT58. This analysis aims at discuss the influence of these parameters on the simulation results focusing on the initial force peak and the average crush load, regarding results realism and instabilities such as large elements deformation and abnormal peak values. Also, the impact of the number of CPUs involved in the simulation calculation is presented. Recommendations are given to set the mesh size and the NIP. TSIZE value should be selected regarding the simulation time step. On the other hand, ERODS has to be adjusted manually. Both are determinant for simulation robustness. Further studies are proposed to find out the reasons of large element deformation.

An Assessment of Structural Details in Lightweight Marine Structures

2004 ◽  
Author(s):  
Carlos A. Pereira ◽  
Paulo P. Silva ◽  
Anto´nio F. Mateus ◽  
Joel A. Witz
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Failure Modes ◽  
Marine Structures ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Structural Details ◽  
Concentration Factors ◽  
Stress Concentration Factors

This paper presents the results of investigations into the mechanics and failure modes of structural details usually encountered in lightweight marine structures. The structural analyses are performed using non-linear finite element analysis. The stress concentration factors and expected fatigue lives of the as designed and the as built structural details are evaluated and alternative configurations are discussed with the aim of improving the designs for production.

Axial impact behaviors of stub concrete-filled square steel tubes

2019 ◽  
Vol 22 (11) ◽  
pp. 2490-2503 ◽  
Author(s):  
YT Zhang ◽  
B Shan ◽  
Y Xiao
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Steel Tube ◽  
Experimental Results ◽  
Parameter Analysis ◽  
Steel Tubes ◽  
Simple Method ◽  
Concrete Filled Steel Tube ◽  
Drop Weight ◽  
The Impact

Existing research on the widely used concrete-filled steel tubes is mainly focused on static or cyclic loading, and the studies on effects of high strain rate are relatively rare. In this article, seven stub concrete-filled steel tubular columns with square section were tested under both static and impact loads, using a large-capacity drop-weight testing machine. The research parameters were variable height of the drop-weight and different load types. The experimental results show that the failure modes of the concrete-filled steel tube columns from the impact tests are similar with those under static load, characterized by the local buckling of the steel tube. The time history curves of impact force and steel strain were investigated. The results indicate that with increasing impact energy, the concrete-filled steel tube stub columns had a stronger impact-resistant behavior. The dynamic analysis software LS-DYNA was employed to simulate the impact behaviors of the concrete-filled steel tube specimens, and the finite element results were reasonable compared with the test results. The parameter analysis on the impact behavior of concrete-filled steel tube columns was performed using the finite element model as well. A simple method was proposed to calculate the impact strength of square concrete-filled steel tube columns and compared favorably with experimental results.

Behaviour of hollow concrete masonry walls with one-course bond beams subjected to concentric and eccentric concentrated loading

2003 ◽  
Vol 30 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Junyi Yi ◽  
Nigel G Shrive
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Three Dimensional ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Concentrated Load ◽  
Concrete Masonry ◽  
Out Of Plane ◽  
Concentrated Loading ◽  
Concrete Masonry Walls

Three-dimensional finite element models of unreinforced hollow concrete masonry walls with one-course bond beams subjected to concentrated loading have been analyzed. The walls were modelled with different loading plate sizes, different loading locations along the wall (at the midpoint of the wall, at the end of the wall, and between these points), and different out-of-plane eccentricities (e = 0, t/6, and t/3). The hollow block units, mortar, grout, and bond beam blocks in the walls were modelled separately. Both smeared and discrete cracking methods have been utilized for predicting cracking under load. Geometric and material nonlinearities and damage due to progressive cracking were taken into account in the analyses. The predicted failure modes and ultimate capacities of the walls with the concentric concentrated load applied at the midpoint or at the end of the wall compared very well with the experimental results. When the load was between the midpoint and the end of the wall, the predicted ultimate capacity was between those for the load at the midpoint and at the end. The strength of the walls decreases with increasing out-of-plane eccentricities.Key words: finite element models, hollow masonry, smeared and discrete cracking models, concentrated load, loading locations, out-of-plane eccentricities.

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

scholarly journals Effect of Mesh Density on Finite Element Analysis Simulation of a Support Bracket

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Nicholas S Gukop ◽  
Peter M Kamtu ◽  
Bildad D Lengs ◽  
Alkali Babawuya ◽  
Adesanmi Adegoke
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computation Time ◽  
Mesh Size ◽  
High Quality ◽  
Element Analysis ◽  
Fine Mesh ◽  
Finite Element Analysis Simulation ◽  
Mesh Analysis ◽  
Mesh Density

Investigation on the effect of mesh density on the analysis of simple support bracket was conducted using Finite element analysis simulation. Multiple analyses were carried out with mesh refinement from coarse mesh of 3.5 mm to a high-quality fine mesh with element size of 0.35 mm under 15 kN loading. Controlled mesh analysis was also conducted for the same loading. At the mesh size of 0.35 mm, it has a maximum stress value of 42.7 MPa. As the element size was reduced, it was observed that below 1.5 mm (higher mesh density) there was no significant increase in the peak stress value; the stress at this level increased by 0.028 % only. Further decreased of mesh size shows insignificant effect on the stresses and displacements for the high-quality fine mesh analysis. The application of High-quality mesh control analysis showed a significant reduction in the computation time by more than 90%. Regardless of the reduction in computation time, the controlled mesh analysis achieved more than 99% accuracy as compared to high-quality fine mesh analysis. Keywords— Computation time, Finite Element Analysis, Mesh density, Support Bracket.

Nonlinear Dynamic Explicit Simulation of a Blast Load on a Building

2004 ◽  
Author(s):  
Siavash Khajehpour ◽  
Greg D. Morandin ◽  
Richard G. Sauve´
Keyword(s):  
Shock Wave ◽  
Finite Element ◽  
Three Dimensional ◽  
Main Roof ◽  
Finite Element Models ◽  
Blast Parameters ◽  
Building Area ◽  
Explicit Simulation ◽  
Potential Damage ◽  
The Impact

The response of buildings to a pressure pulse from a shock wave is becoming more critical to design assessments. The severe loading transients resulting from such events, provides unique challenges to analytical modelling and simulation of building survivability. In this paper, a nonlinear explicit three dimensional blast simulation of a building is undertaken with critical contents located in the most susceptible locations in order to provide an assessment of potential damage and the impact on the contents of interest. In the work described in this paper, the source and orientation of the blast relative to the building are outlined. Using developed blast procedures, the amplitude and impulse of the blast shock wave due to specified blast parameters are determined for the front, sides, roof and rear of the building. These are applied to finite element models of the building. A state-of-the-art, large deformation, non-linear finite element code that is well suited to this class of problem, is used in the blast simulations. The results indicate that the building is severely damaged, however, the internal building area, in the vicinity of the critical contents, is intact and the main roof trusses remain attached.

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