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dynamic responses of Cellular Metal-Filled Steel Beam-Column Joint Under Impact Loading

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Journal of Shanghai Jiaotong university(Science) 2020年第3期25卷 384-393页

作者： DING Kewei LIU Jianhua REN Jianwei MA Wei College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China Provincial Key Laboratory for Architectural Structure and Underground Engineering Anhui Jianzhu UniversityHefei 230601China

Taking the excellent energy absorption performances of cellular structures into consideration,three beam-column steel joints are proposed to analyze the effect of cellular metallic fillers on impact mechanical responses of beam-column *** on the existing experimental results,the finite element models of the associated joints are established by using finite element method *** deformation mode,the bearing capacity and energy absorption performance of various joints subjected to impact loadings with the loading velocities from 10 to 100 m/s are analyzed,*** dynamic responses of cellular metal-filled beamcolumn joints are quantitatively analyzed by means of displacements of central region,nominal impacting stress and energy absorption *** results can be concluded that the filling of cellular filler weakens the stress concentration on joints,alleviates the occurrence of tearing in connection region among column and beam,and reduces the displacement caused by impact *** absorption efficiency of filled joints subjected to impact loading increases as the impacting velocity increases,and the cellular metallic filler improves their impact resistance of beam-column *** energy absorption efficiency of fully filled joints is superior to that of *** study can provide a reference for steel structural design and post-disaster repair under extreme working conditions.

关键词： steel beam-column joint cellular metal material impact loading dynamic responses impact energy absorption

A method to Estimate dynamic responses of VLFS Based on Multi-Floating-Module Model Connected by Elastic Hinges

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China Ocean Engineering 2021年第5期35卷 687-699页

作者： HUANG Heng CHEN Xu-jun LIU Jun-yi MIAO Yu-ji JI Song College of Field Engineering Army Engineering University of PLANanjing 210007China China Ship Scientific Research Center Wuxi 214082China

Based on the elastic foundation beam theory and the multi-floating-module hydrodynamic theory,a novel method is proposed to estimate the dynamic responses of VLFS(Very Large Floating Structure).In still water,a VLFS can be simplified as an elastic foundation beam model or a multi-floating-module model connected by elastic *** to equivalent displacement of the two models in static analysis,the problem of rotation stiffness of elastic hinges can be ***,based on the potential flow theory,the dynamic responding analysis of multi-floatingmodule model under wave loads can be computed in ANSYS-AQWA *** assembling the time domain analysis results of each module,the dynamic responses of the VLFS can be *** of the method is conducted through a series of comparison calculations,which mainly includes a continuous structure and a three-part structure connected by hinges in regular *** results of this paper method show a satisfactory agreement with the experiment and calculation data given in relative references.

关键词： Very Large Floating Structure(VLFS) dynamic responses elastic foundation beam multi-floatingmodule model elastic hinge

Predicting Loads and dynamic responses of An Offshore Jacket Wind Turbine in A Nonlinear Sea

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China Ocean Engineering 2020年第5期34卷 641-650页

作者： WANG Ying-guang State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In order to improve the simulation efficiency, a novel transformed linear Gaussian model has been first proposed in this paper for generating equivalent "nonlinear" irregular waves. It is demonstrated by calculation examples that for obtaining equivalent "nonlinear" waves with the same accuracy, the transformed linear Gaussian model is about 2.7 times faster than the traditional nonlinear simulation method and is about 2.14 times faster than the method proposed by Agarwal and Manuel(2011). The loads and dynamic responses calculation results regarding an offshore jacket wind turbine in this paper demonstrate that nonlinearly simulated irregular waves with bottom effects should be considered in order to design an un-conservative support structure for the offshore wind turbine. Furthermore, by studying the calculation results in this article we have found that the loads and dynamic responses of the offshore wind turbine when inputting transformed linearly simulated waves with bottom effects are almost identical to the corresponding values when inputting nonlinearly simulated waves with bottom effects. All these calculation results clearly demonstrate the superiority and effectiveness of using our novel transformed linear Gaussian model for predicting the wave loads and dynamic responses of an offshore wind turbine operating in a realistic nonlinear sea with bottom effects.

关键词： loads dynamic responses offshore wind turbine bottom effects nonlinear irregular sea

Efficient computation for dynamic responses of systems with time-varying characteristics

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Acta Mechanica Sinica 2009年第5期25卷 699-705页

作者： Liang Ma Yudong Chen Suhuan Chen Guangwei Meng Department of Mechanics, Nanling Campus,Jilin University, 130025 Changchun, China Department of Mechanics Nanling Campus Jilin University Changchun China

Based on Neumman series and epsilon-algorithm, an efficient computation for dynamic responses of systems with arbitrary time-varying characteristics is investigated. Avoiding the calculation for the inverses of the equivalent stiffness matrices in each time step, the computation effort of the proposed method is reduced compared with the full analysis of Newmark method. The validity and applications of the proposed method are illustrated by a 4-DOF spring-mass system with periodical time-varying stiffness properties and a truss structure with arbitrary time-varying lumped mass. It shows that good approximate results can be obtained by the proposed method compared with the responses obtained by the full analysis of Newmark method.

关键词： dynamic responses Efficient computation Epsilon-algorithm Time-varying characteristics

Closed-form solution for dynamic responses of shaft-tunnel junction under uniform P waves

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Underground Space 2022年第3期7卷 352-362页

作者： Jinghua Zhang Yong Yuan Mingqing Xiao Yao Yin a Qing Sun Department of Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China China Railway Siyuan Survey and Design Group Co. Wuhan 430063China

This paper discusses the special situation when a shaft-tunnel junction is subject to vertically propagating P *** a complicated system like the shaft-tunnel junction,it is necessary to investigate the most basic cases firstly,and the responses induced by uniform P waves are one of *** this end,a closed-form solution is derived from the classical differential equation describing the forced vibration of a single degree-of-freedom *** key issue is the characterization of the coupled dynamic interactions among the shaft,the tunnel,and the *** paradigm regards the three of them as a massive rigid body,a continuous Euler-Bernoulli beam,and a set of supporting elements,*** final solution is to calculate the displacements of the shaft and the tunnel in the form of two compact equations,and the internal forces of the tunnel are therefore easily *** means of a finite element simulation,the validity as well as the accuracy of the closed-form solution is *** solution provides an explicit comprehension of the coupled dynamic interactions and thus enhances the understanding of the dynamic mechanics of the shaft-tunnel junction.

关键词： Shaft-tunnel junction dynamic responses Closed-form solution P waves

dynamic responses of Long-Span Transmission Tower-Line System Subjected to Broken Wires

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Journal of Southwest Jiaotong University(English Edition) 2008年第4期16卷 309-319页

作者：夏正春李黎方秦汉龙晓鸿 School of Civil Engineering and Mechanics Huazhong University of Science and Technology

A macroscopic finite element modeling approach was proposed to calculate the vibration of a tower-line system subjected to broken wires with software ANSYS/LS-DYNA. In the finite element model, not only the nonlinearity of wires and suspension insulators are considered, but also the support towers are included. The incremental and iterative approaches are combined by applying the unbalanced loads incrementally during each iteration cycle. The approach was illustrated with an example of a Hanjiang- River long-span transmission line system subjected to a shield wire and a conductor failure, respectively. The analysis results showed that the proposed dynamic simulation approach can demonstrate the kinetic process of the tower-line system subjected to wire ruptures： The frequencies of line components were lower and densely distributed, but the frequencies of tower components were higher and sparsely distributed. Anyhow, the dynamic effects of wire ruptures on tower-line system could not be ignored in analysis of tower-line system subjected wire failures.

关键词： Electric transmission Tower-line coupling Wire rupture dynamic responses ANSYS/LS-DYNA

Explicit–Implicit Co-Simulation Techniques for dynamic responses of a Passenger Car on Arbitrary Road Surfaces

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Engineering 2019年第6期5卷 1171-1178页

作者： Hongzhou Hu Zhihua Zhong State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

To study the durability of a passenger car, this work investigates numerical simulation techniques. The investigations are based on an explicit implicit approach in which substructure techniques are used to reduce the simulation time, allowing full vehicle dynamic analyses to be performed on a timescale that is dif cult or impossible with the conventional nite element model (FEM). The model used here includes all necessary nonlinearities in order to maintain accuracy. All key components of the car structure are modeled with deformable materials. Tire road interactions are modeled in the explicit package with contact-impact interfaces with arbitrary frictional and geometric properties. Key parameters of the responses of the car driven on six different kinds of test road surfaces are examined and compared with experimental values. It can be concluded that the explicit implicit co-simulation techniques used here are ef cient and accurate enough for engineering purposes. This paper also discusses the limitations of the proposed method and outlines possible improvements for future work.

关键词： Durability study dynamic responses Passenger car Explicit–implicit co-simulation Contact-impact Friction Substructures

Investigation on the dynamic responses of a Truss Spar Platform for Different Mooring Line Groups

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Journal of Marine Science and Application 2015年第2期14卷 189-195页

作者： Montasir Osman Ahmed Anurag Yenduri V. J. Kurian Department of Civil Engineering Universiti Teknologi PETRONAS Tronoh Perak 31750 Malaysia

The dynamic responses of any floating platform arc dependent on the mass, stiffness and damping characteristics of the body as well as mooring system. Therefore, it is very essential to study the effect of individual contributions to the system that can finally help to economise their cost. This paper focuses on the effect of mooring stiffness on the responses of a truss spar platform, obtained by different grouping of lines. The study is part of our present researches on mooring systems which include the effect of line pretension, diameter and azimuth angles. The platform is modelled as a rigid body with three degrees-of-freedom and its motions are analyzed in time-domain using the implicit Newmark Beta technique. The mooring lines restoring force-excursion relationship is evaluated using a quasi-static approach. It is observed that the mooring system with lines arranged in less number of groups exhibits better performance in terms of the restoring forces as well as mean position of platform. However, the dynamic motions of platform remain unaffected for different line groups.

关键词： mooring system mooring lines, spar platform motionresponses Newmark Beta method Morison equation quasi-staticapproach dynamic responses

Elastic responses of underground circular arches considering dynamic soil-structure interaction:A theoretical analysis

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Acta Mechanica Sinica 2013年第1期29卷 110-122页

作者： Hai-Long Chen Feng-Nian Jin Hua-Lin Fan PLA University of Science and Technology Key Laboratory of Bridge-structure Engineering Chongqing Jiaotong University Laboratory of Structural Analysis for Defense Engineering and Equipment College of Mechanics and Materials Hohai University Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province Lanzhou Jiaotong University

Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equa- tion of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal super- position. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.

关键词： Underground protective arches - dynamic soilstructure interaction dynamic responses Analytical solution