Numerical analysis of the counter-intuitive dynamic behavior of the elastic-plastic pin-ended beams under impulsive loading with regard to linear hardening effects

2018 ◽  
Vol 232 (24) ◽  
pp. 4588-4600 ◽  
Author(s):  
Mehdi Shams Alizadeh ◽  
Kourosh Heidari Shirazi ◽  
Shapour Moradi ◽  
Hamid Mohammad Sedighi
Keyword(s):  
Finite Element ◽  
Galerkin Method ◽  
Dynamic Behavior ◽  
Structural Parameters ◽  
Time History ◽  
Anomalous Behavior ◽  
Impulsive Loading ◽  
Linear Hardening ◽  
Elastic Plastic ◽  
Finite Element Software

The counter-intuitive behavior where the permanent deflection of elastic-plastic beam come to rest in the opposite direction of the impulsive loading, normally appears and disappears abruptly, in certain small ranges of loading and structural parameters. One of the most important issues in the study of this phenomenon is the determination of the influence of different parameters. This work is aimed to study the effects of hardening in counter-intuitive dynamic behavior of elastic-plastic pin-ended beams under impulsive loading. This has been done by developing the proposed Galerkin numerical model and presenting a novel algorithm. The Galerkin method as well as the commercial finite element code ANSYS/LS-DYNA is applied to study this phenomenon. In order to account for the hardening effects in Galerkin method, a new algorithm is proposed. The time history curves for mid-span of the beam is studied in detail and the region of the occurrence of the counter-intuitive behavior is determined. Furthermore, using the finite element software, energy diagrams of the beam are also derived. It has been found that the counter-intuitive behavior is a phenomenon, which is very sensitive to loading, therefore it may appear with a little change in the amount of loading. The results also show that although both methods predict one continuous region of loading for the occurrence of this phenomenon in elastic-perfectly plastic beams, still there are two continuous distinct regions of loading, when considering the hardening effects, for this phenomenon. In addition, this anomalous behavior would occur in the proper ratios of kinetic to internal energy and when considering the linear hardening effects, the possibility of the occurrence of the counter-intuitive behavior exists in a wider domain of energy ratio.

scholarly journals The Key Construction Technology Research on the Intercontinental Shanghai Wonderland

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Peng Jiang ◽  
Shaole Yu ◽  
Wei Luan ◽  
Xinxi Chen ◽  
Yang Qin ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Safety Margin ◽  
Time History ◽  
Construction Technology ◽  
Construction Process ◽  
Component Size ◽  
Finite Element Software ◽  
Deep Pit ◽  
The Stability

The Intercontinental Shanghai Wonderland is the first natural ecological hotel built in an abandoned mine in the world, which faces many difficulties in the construction process. To solve the difficult problems in the construction process, the study was carried out from the stability analysis of the deep pit cliff, the mechanical performance of the structure, and the construction technology. The Intercontinental Shanghai Wonderland is built around the abandoned deep pit cliffs, and the stability of the deep pit cliffs directly affects the safety of the building. The dynamic response characteristics and the instability characteristics of the mine slope under the dynamic response were analyzed by a three-dimensional dynamic finite element method. The calculation results showed that with effective anchoring support measures, the stability coefficient of slope under static load and small earthquakes was large, which had a certain safety margin. Under the action of large earthquakes, the slope could still meet the stability requirements. The structure of the Intercontinental Shanghai Wonderland is a unique two-point support structure system. It shows the deformation and stress characteristics of one fixed end and one simply supported end under horizontal load. The elastic-plastic time history response of structures under actions of rare earthquakes was analyzed through the finite element analysis software. The analysis results show that the current structural system along with the design of component size and strength can meet the seismic performance of the structure under actions of rare earthquakes. The Intercontinental Shanghai Wonderland was built in a stone pit 88 m below the surface. Therefore, the transportation of materials was a difficulty in the construction process. A set of ultradeep concrete downward conveying equipment was invented to solve the difficulty. The construction process of the whole structure was simulated by finite element software, which provided a safety guarantee for the construction of the whole structure.

Elastic-Plastic Time History Analysis of Self-Anchored Cable-Stayed Suspension Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 4295-4300
Author(s):  
Feng Miao ◽  
Lei Shi ◽  
Zhe Zhang
Keyword(s):  
Plastic Hinge ◽  
Time History ◽  
Seismic Energy ◽  
Suspension Bridge ◽  
Time History Analysis ◽  
Main Beam ◽  
Elastic Plastic ◽  
Finite Element Software ◽  
Axial Forces ◽  
History Analysis

Base on the elastic-plastic analytical theory, an elastic-plastic time-history analysis of self-anchored cable-stayed suspension bridge, which engineering background is Dalian Gulf Cross-sea Bridge program, is performed by using general finite element software Midas/Civil. The material nonlinearity of structure is considered with reinforcement concrete fiber model, and distributed hinge type is adopted to simulate for plastic hinge. Compared with the results of an elastic time-history analysis, it is shown that for the structure into the elastic-plastic stage, because of the production of plastic hinge, the input seismic energy is dissipated partially, and the internal forces of structural elements are reduced. The bending moments and axial forces occur mainly in the main tower root. Furthermore, the rotation properties of the plastic hinge causes displacement increasing of certain parts of the structure, which assumes mainly the vertical displacement present on the top of main tower and the main beam. In conclusion, it is proposed that caging devices are set in the design.

Crack Growth Direction Analysis Based on Elastic-Plastic Property of Material

2011 ◽  
Vol 217-218 ◽  
pp. 101-106
Author(s):  
Zhi Ping Yin ◽  
Jiong Zhang ◽  
Jin Guo ◽  
Qi Qing Huang
Keyword(s):  
Finite Element ◽  
Deflection Angle ◽  
Element Model ◽  
Plastic Property ◽  
Maximum Tensile Stress ◽  
Growth Direction ◽  
Crack Deflection ◽  
Cross Sectional ◽  
Elastic Plastic ◽  
Finite Element Software

The finite element software ANSYS was employed to create a finite element model of the cracked wing beam integrated structure, and the stress field of the crack tip was got by the material nonlinearity (elastic-plastic) analysis method. Based on the maximum tensile stress theory criteria, the crack deflection angle was obtained. The crack deflection angles with different geometry parameters (crack length, wed thickness, the height-thickness ratio of the stringer, cross-sectional area, and the location of the stringer) of the wing beam integrated structure were calculated and compared with each other. So the influences of the geometry parameters of the wing beam integrated structure on the crack deflection were studied. The crack deflection angles obtained in elastic analyzing and elastic-plastic analyzing were compared to investigate the effects of the material property on the crack deflection angle.

Numerical analysis of the counterintuitive dynamic behavior of the elastic-plastic fully-clamped beams under impulsive loading

Mechanika ◽  
2017 ◽  
Vol 23 (1) ◽  
Author(s):  
Mehdi Shams Alizadeh ◽  
Kourosh Heidari Shirazi ◽  
Shapour Moradi ◽  
Hamid Mohammad Sedighi
Keyword(s):  
Numerical Analysis ◽  
Dynamic Behavior ◽  
Impulsive Loading ◽  
Elastic Plastic ◽  
Clamped Beams

Seismic Response Analysis of Twin-Tower Building with Enlarged Base

2014 ◽  
Vol 912-914 ◽  
pp. 1534-1537
Author(s):  
Shao Bo Zhang ◽  
Ke Lun Wei ◽  
Bi Jian Xiao
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Boundary Conditions ◽  
Seismic Response ◽  
Time History ◽  
Response Analysis ◽  
Rigid Boundary ◽  
Finite Element Software ◽  
Elastic Boundary ◽  
Elastic Boundary Conditions

This paper adopts large finite element software ANSYS to establish finite element model of twin-tower building with enlarged base, uses dynamic time history analysis method for seismic response calculation, compare and analyze the calculation results of twin-tower building with enlarged base under elastic boundary conditions and rigid boundary conditions. The results showe that dynamic response for model under elastic boundary conditions is larger than dynamic response for model under rigid boundary conditions, and elastic boundary conditions is more close to the actual situation.

Optimization Dressing Method of Amplitude Transformer Based on Finite Element

2013 ◽  
Vol 278-280 ◽  
pp. 315-318
Author(s):  
Ming Li Zhao ◽  
Bo Zhao ◽  
Yu Qing Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Resonant Frequency ◽  
Structural Parameters ◽  
Low Cost ◽  
Dressing Method ◽  
Finite Element Software ◽  
System Vibration ◽  
Vibration Performance ◽  
Element Method

The node position of amplitude transformer was determined by the finite element method, and the flange was designed at the nod position for conveniently installation. By the finite element software, the amplitude transformer with flange was optimized and dressed, and its structural parameters were determined. During the actual manufacturing process, it was used impedance analyzer to test its vibration performance, the testing results show that this system vibration performance is good, its resonant frequency is 34.771kHz, anti-resonant frequency is 35.008kHz. The above-mentioned results are very much coincided with the system natural frequency of 34.893kHz which is drew by finite element method. Compared to the traditional dressing this method has many advantages such as convenience, green, environmental protection, low cost and others.

scholarly journals Finite-Element-Based Multiple Normal Loading-Unloading of an Elastic-Plastic Spherical Stick Contact

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Biplab Chatterjee ◽  
Prasanta Sahoo
Keyword(s):  
Finite Element ◽  
Strain Hardening ◽  
Tangent Modulus ◽  
Repeated Loading ◽  
Normal Loading ◽  
Elastic Plastic ◽  
Finite Element Software ◽  
Hardening Models ◽  
Hardening Rules ◽  
Contact Parameters

The repeated normal elastic plastic contact problem of a deformable sphere against a rigid flat under full stick contact condition is investigated with a commercial finite element software ANSYS. Emphasis is placed on the effect of strain hardening and hardening model with the maximum interference of load ranging from elastic to fully plastic, which has not yet been reported. Different values of tangent modulus coupled with isotropic and kinematic hardening models are considered to study their influence on contact parameters. Up to ten normal loading-unloading cycles are applied with a maximum interference of 200 times the interference required to initiate yielding. Results for the variation of mean contact pressure, contact load, residual interference, and contact area with the increasing number of loading unloading cycles at high hardening parameter as well as for low tangent modulus with two different hardening models are presented. Results are compared with available finite element simulations and in situ results reported in the literature. It is found that small variation of tangent modulus results in same shakedown behavior and similar interfacial parameters in repeated loading-unloading with both the hardening rules. However at high tangent modulus, the strain hardening and hardening rules have strong influence on contact parameters.

scholarly journals Study of the Forming Characteristics of Small-Caliber Ammunition with Circumferential MEFP

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 891 ◽  
Author(s):  
Guangsong Ma ◽  
Guanglin He ◽  
Yukuan Liu ◽  
Yachao Guo
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Structural Parameters ◽  
Outer Wall ◽  
Diameter Ratio ◽  
Curvature Radius ◽  
Preliminary Design ◽  
Finite Element Software ◽  
Forming Characteristics ◽  
Simulation Results

To study the influence of the structural parameters of the ammunition liner of small-caliber ammunition on the forming characteristics of the projectile, an integrated circumferential multiple explosively formed projectile (MEFP) warhead with an integrated shell and the liner was initially designed, and the wall thickness of the liner is variable. LS-DYNA finite-element software is used to simulate the integral circumferential MEFP of the preliminary design, based on the numerical simulation results, the influence of the thickness at the center of the liner, and the curvature radius of the liner on the shape and velocity of the formed projectile. The numerical simulation results show that when the thickness of the center of the liner is constant and the curvature radius increases gradually, the velocity of the formed projectile decreases and the length: Diameter ratio of formed projectile decreases gradually. When the curvature radius of the liner remains unchanged, the velocity of the formed projectile decreases with the increase of the thickness of the center of the liner, and the shape of the formed projectile does not change significantly. The results show that when the design of integrating the shell and the liner was adopted for the integral circumferential MEFP warhead, the shape of the formed projectile is greatly affected by the curvature radius of the liner (curvature radius of inner and outer walls of the liner), but less by the thickness of the center of the liner. The velocity of the formed projectile is affected by the curvature radius of the inner and outer walls of the liner and the thickness of the center of the liner. Moreover, the influence of the thickness of the center of the liner on the velocity of the formed projectile is greater than that of the curvature radius of the outer wall of the liner.

scholarly journals Numerical modelling of dynamic stability of RCC dam

2018 ◽  
Vol 195 ◽  
pp. 03021
Author(s):  
Omer Mughieda ◽  
Kenan Hazirbaba ◽  
Khaldoon Bani-Hani ◽  
Wassim Daoud
Keyword(s):  
Finite Element ◽  
Structural Stability ◽  
Response Spectrum ◽  
Time History ◽  
The Body ◽  
Roller Compacted Concrete ◽  
Finite Element Software ◽  
Rcc Dam ◽  
Stability Against Sliding ◽  
The Stability

Stability and stress analyses are the most important elements that require rigorous consideration in design of a dam structure. In the current research, dynamic structural stability of a roller-compacted-concrete (RCC) dam was performed. The RCC dam was modeled using the finite element method to investigate the stability against sliding and the structural stability of the body of the dam. The commercially available finite element software (SAP 2000) was used to analyze stresses in the body of the dam and foundation. A linear finite element dynamic analysis was performed. Response spectrum and time history methods were used with different earthquake loads. The response spectrum of the 1995 Aqaba earthquake and a representative elastic-spectrum with smooth plateau for both Operating Basis Earthquake (OBE) and Maximum Credible Earthquake (MCE) were used in this study. The analysis was carried out assuming that no slip will occur at the interface between the dam and the foundation. The greatest tension was found to develop in the rock adjacent to the toe of the upstream slope. The factor of safety against sliding along the entire base of the dam was found to be greater than 1 (FS>1), for both loading conditions.

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