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

2016 ◽  
Author(s):  
Bin Liu ◽  
C. Guedes Soares
Keyword(s):  
Cross Section ◽  
Failure Modes ◽  
Rectangular Cross Section ◽  
Central Position ◽  
Plastic Response ◽  
Deformation And Failure ◽  
Impact Location ◽  
Initiation And Propagation ◽  
Material Fracture ◽  
The Impact

Drop weight impact tests are performed to examine the plastic response and failure of clamped rectangular cross-section tubes struck transversely by a hemispherical indenter. The laboratory results are compared with numerical simulations. The span lengths of the tube specimens are 125 and 250 mm, and they are impacted at the mid-span and the quarter-span. Moreover, the impact point along the width direction is located at the central position and displaced 10 mm from the centre, respectively. The results show that the impact location strongly influences the impact response of the tubes. The experimental results are presented in terms of the force-displacement responses and the failure modes, showing a good agreement with the simulations performed by the LS-DYNA finite element solver. The numerical results manage to describe the process of initiation and propagation of the material fracture and provide detailed information to analyse the large inelastic deformation and failure of tubular components subjected to impact loading. The deformation and failure characteristics of the rectangular tubes are well described on the basis of 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 elaborated.

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.

Design, Simulation and Testing of Overpack Encapsulation Vessels

2012 ◽  
Author(s):  
A. Towse ◽  
J. Dodds
Keyword(s):  
Pressure Vessel ◽  
High Speed ◽  
Failure Modes ◽  
Inner Product ◽  
Central Position ◽  
Video Footage ◽  
Rule Approach ◽  
The Moment ◽  
Explicit Dynamic ◽  
The Impact

The paper presents an overpack designed to contain nuclear product cans which may become pressurised or contaminated. The overpack provides a protective barrier to an inner product can, and due to the possibility of leakage of gas from the contents, the overpack must also function as a pressure vessel. Furthermore, the overpack is required to provide physical protection to the inner can and proof of containment was therefore necessary under a number of different impact scenarios, both pre-pressurised and also with the simulation of pressurisation at the moment of impact. Additionally, the inner product can was to be maintained in a central position during the deceleration at impact. This paper focuses on the analytical design and substantiation of the impact of the system which was performed using an explicit dynamic solver for a number of impact orientations. The design of the overpack to satisfy the relevant pressure vessel Code are not discussed in detail. The potential failure modes of the overpack during impact were assessed and design improvements made over a number of iterations. Following completion of the design and simulation phase, prototypes were built and tested to verify the engineering design and analysis. The testing showed that simulation driven design in conjunction with a pressure vessel design by rule approach was successful in creating a solution for the product can encapsulation. A comparison between the analytical simulation and high-speed video footage of the testing was also made.

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.

Heat Transfer and Pressure Drop Correlation for Helicoidal Pipes of Rectangular Cross Section

2009 ◽  
Author(s):  
Christopher Katinas ◽  
Ahmad Fakheri
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Aspect Ratio ◽  
Friction Factor ◽  
Cross Section ◽  
Numerical Solutions ◽  
Rectangular Cross Section ◽  
Dean Number ◽  
Curvature Effects ◽  
The Impact

In this study, flow and heat transfer for laminar flow in curved channels of rectangular cross section is examined. The focus of the numerical solutions is on rectangular cross sections with an aspect ratio less than one, since little information is available for heat transfer in curved rectangular pipes whose width is greater than height. The study examines the impact of the aspect ratio and Dean number on both friction factor and Nusselt number. The results show that although both friction factor and Nusselt number increase as a result of curvature effects, the heat transfer enhancements significantly outweigh the friction factor penalty. Numerical solutions in this study consider the more realistic case of hydrodynamically developed and thermally developing flow.

Study of Diffusion Characteristics of Pollutant in Flowing Water

2011 ◽  
Vol 403-408 ◽  
pp. 2671-2674
Author(s):  
Mei Jing Wang ◽  
Lin Luo
Keyword(s):  
Cross Section ◽  
Water Surface ◽  
Concentration Distribution ◽  
Rectangular Cross Section ◽  
Flowing Water ◽  
River Bed ◽  
Front Position ◽  
Diffusion Characteristics ◽  
Instantaneous Point ◽  
The Impact

By considering the impact of the walls, water surface and river bed in straight and rectangular cross-section channel and analyzing concentration distribution of instantaneous point source, diffusion characteristics of pollutant were obtained that: (1) the vertical front position of pollutant, zf, is proportional to 0.5 power of t; (2) the velocity of vertical front position, Vf, is inverse-proportion to the vertical front position, zf; (3) the vertical front position, zf, is proportional to the transverse front position, yf.

scholarly journals A generalized model for dynamic deformation and failure of clamped beam under impact loading

2018 ◽  
Vol 474 (2215) ◽  
pp. 20170799
Author(s):  
Subhajit Sen ◽  
Amit Shaw
Keyword(s):  
Plastic Deformation ◽  
Impact Loading ◽  
Failure Modes ◽  
Dynamic Behaviour ◽  
Plastic Hinge ◽  
Impact Point ◽  
Deformation And Failure ◽  
Deformation And Fracture ◽  
Time Histories ◽  
The Impact

A mathematical model representing the dynamic behaviour (both plastic deformation and fracture) of a clamped beam under impact loading is developed. Indentation at the impact point, transverse deformation, formation and propagation of plastic hinge, arrest of plastic hinge leading to plastic work concentration and finally failure are the physical processes which constitute the basis of the derived model. The effect of imperfection is also incorporated. Imperfection is considered in the form of a π -shaped notch located at the impact point, at supports or at both. The distinct feature of the present formulation is that it accommodates different possible deformation and failure modes in a single model. Final plastic deformation, time histories of different field variables and failure modes as predicted from the derived model are found to be in good agreement with the corresponding experimental and numerical results. This model provides a quick understanding of the dynamic behaviour of beam under impact and also the effect of various underlying parameters which may be useful for forming design provisions for impact-resistant structures.

Impact Response and Failure Mode for Single-Layer Geodesic Spherical Domes under Impact Load

2013 ◽  
Vol 351-352 ◽  
pp. 80-84
Author(s):  
Duo Zhi Wang ◽  
Feng Fan ◽  
Xu Dong Zhi ◽  
Jun Wu Dai
Keyword(s):  
Dynamic Response ◽  
Failure Mode ◽  
Failure Modes ◽  
Impact Load ◽  
Single Layer ◽  
Impact Response ◽  
Impact Location ◽  
Parametric Analyses ◽  
The Impact ◽  
Local Dent

Based on the ANSYS/LS-DYNA software, the analysis for the 40m span geodesic spherical domes under impact load is carried out. By changing the mass of impact object, impact velocity and impact location, the parametric analyses on the dynamic response of the structures under the impact loading are carried out. The three failure modes of the spherical domes are summed up: local dent of structure and global collapse of structure, Punch failure of structure. Then the characteristics of the dynamic response of the structure with different failure mode, such as the impact course, impact load, speed of nodes, displacement of nodes, and stress of bars, are investigated. It is further improvement of failure mode for single-layer reticulated dome under impact.

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