scholarly journals Dynamic Response Analysis of Cable of Submerged Floating Tunnel under Hydrodynamic Force and Earthquake

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Zhiwen Wu ◽  
Guoxiong Mei
Keyword(s):  
Dynamic Response ◽  
Hydrodynamic Force ◽  
Structural Parameters ◽  
Beam Theory ◽  
Response Analysis ◽  
Analysis Model ◽  
Euler Beam ◽  
Earthquake Excitation ◽  
Submerged Floating Tunnel ◽  
The Time Domain

A simplified analysis model of cable for submerged floating tunnel subjected to parametrically excited vibrations in the ocean environment is proposed in this investigation. The equation of motion of the cable is obtained by a mathematical method utilizing the Euler beam theory and the Galerkin method. The hydrodynamic force induced by earthquake excitations is formulated to simulate real seaquake conditions. The random earthquake excitation in the time domain is formulated by the stochastic phase spectrum method. An analytical model for analyzing the cable for submerged floating tunnel subjected to combined hydrodynamic forces and earthquake excitations is then developed. The sensitivity of key parameters including the hydrodynamic, earthquake, and structural parameters on the dynamic response of the cable is investigated and discussed. The present model enables a preliminary examination of the hydrodynamic and seismic behavior of cable for submerged floating tunnel and can provide valuable recommendations for use in design and operation of anchor systems for submerged floating tunnel.

scholarly journals Gust Response Analysis for Helicopter Rotors in the Hover and Forward Flights

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Linpeng Wang ◽  
Yuting Dai ◽  
Chao Yang
Keyword(s):  
Shear Force ◽  
Thrust Force ◽  
Vertical Direction ◽  
Beam Theory ◽  
Response Analysis ◽  
Forward Flight ◽  
Helicopter Rotors ◽  
Aerodynamic Model ◽  
Aeroelastic Model ◽  
The Time Domain

Dynamic load due to gust for helicopter rotors directly affects the structural stress and flight performance. In case of gust, it may cause the loss of trust force or the increase of deflection for rotors. In current work, an effective coupled aeroelastic model based on a medium-deflection beam theory and a nonlinear unsteady aerodynamic model in the time domain were constructed. Three types of gust in vertical direction were added in the model. The dynamic response and structural load for helicopter rotors under three types of gust were calculated, respectively. Results indicated that when rotors suffer a gust in hover at downward direction, the thrust force on rotor disk would decrease significantly when the gust amplitude increases, which should be paid attention in the design. Among the three gust types with the same gust strength, the maximum instantaneous shear force due to impulse shape gust is the largest. When the rotors suffer a gust in a forward flight, the shear force at the root of rotors would increase with the gust strength first but then it decreases. More attention should be paid to the decrease of thrust force and the increase of structural load in a forward flight.

Dynamic response analysis on vibration of ground and track system induced by metro operation

2019 ◽  
Vol 36 (3) ◽  
pp. 958-970 ◽  
Author(s):  
Zhi Ding ◽  
Danwei Li
Keyword(s):  
Dynamic Response ◽  
Response Analysis ◽  
Analysis Model ◽  
Subway Tunnel ◽  
Ground Field ◽  
Element Analysis ◽  
Foundation Soil ◽  
Double Line ◽  
Content Type ◽  
Track System

PurposeThis paper aims to evaluate the dynamic response of surrounding foundation and study the vibration characteristics of track system.Design/methodology/approachA double-line underground coupling analysis model was established, which included two moving train, track, liner and the ground field.FindingsBased on the 2.5D (D is diameter) finite element analysis, the influence of the important factors such as the depth of the subway tunnel, the nature of the foundation soil, the relative position relation of the double tunnel, the subway driving speed on the foundation and the orbital vibration are analyzed in this article.Originality/valueThe results in paper may have reference value for the prediction of train induced vibrations and for the research of dynamic response of ground field.

Overestimation Analysis of Interval Finite Element for Structural Dynamic Response

2019 ◽  
Vol 11 (04) ◽  
pp. 1950035
Author(s):  
Tuanjie Li ◽  
Hangjia Dong ◽  
Xi Zhao ◽  
Yaqiong Tang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Structural Parameters ◽  
Upper And Lower Bounds ◽  
Response Analysis ◽  
Uncertain Parameters ◽  
Engineering Structures ◽  
Structural Dynamic ◽  
Dynamic Response Analysis ◽  
Interval Parameters

Dynamic response analysis plays an important role for the structural design. For engineering structures, there exist model inaccuracies and structural parameters uncertainties. Consequently, it is necessary to express these uncertain parameters as interval variables and introduce the interval finite element method (IFEM), in which the elements in stiffness matrix, mass matrix and damping matrix are all the function of interval parameters. The dependence of interval parameters leads to overestimation of dynamic response analysis. In order to reduce the overestimation of IFEM, the element-based subinterval perturbation for static analysis is applied to dynamic response analysis. According to the interval range, the interval parameters are divided into different subintervals. With permutation and combination of each subinterval, the upper and lower bounds of displacement response are obtained. Because of the large number of degrees of freedom and uncertain parameters, the Laplace transform is used to evaluate the dynamic response for avoiding to frequently solve the interval finite element linear equations. The numerical examples illustrate the validity and feasibility of the proposed method.

Nonlinear Seismic Response Analysis Method for Steel Mega-Frame Structures Based on Improved Finite Segment Element Plastic Zone Model

2010 ◽  
Vol 150-151 ◽  
pp. 279-283
Author(s):  
Guo Lin Xu ◽  
Ling Xin Zhang ◽  
Ya Shuang Bai
Keyword(s):  
Plastic Zone ◽  
Nonlinear Analysis ◽  
Shear Deformation ◽  
Plastic Hinge ◽  
Beam Theory ◽  
Frame Structures ◽  
Response Analysis ◽  
Zone Model ◽  
Analysis Model ◽  
Finite Segment

When conducting nonlinear analysis of frame structure, we usually adopt plastic hinge model or plastic zone model which based on bending beam theory. But the effect of shear deformation on element deformation are not considered in the analysis model established based on bending beam theory, which is only applicable to the elements with large span depth ratio. For the main structure of steel mega-frame structures, the depth of element section is very high. Thus it can not meet bending beam theory assumption. The common analysis model can not simulate structure reaction accurately. This article puts forward some treatment methods for existing problems of nonlinear analysis of steel mega-frame structures, establish member element stiffness matrix based on improved finite segment element plastic zone model and consider the effect of element shear deformation on plastic development.

Dynamic response analysis for submerged floating tunnel with anchor-cables subjected to sudden cable breakage

2018 ◽  
Vol 59 ◽  
pp. 179-191 ◽  
Author(s):  
Yiqiang Xiang ◽  
Zhengyang Chen ◽  
Ying Yang ◽  
Heng Lin ◽  
Sheng Zhu
Keyword(s):  
Dynamic Response ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Submerged Floating Tunnel

Dynamic Response Analysis under the Metro-Vibration Loading of Xi'an Bell Tower Timber Structure

2012 ◽  
Vol 170-173 ◽  
pp. 1361-1366 ◽  
Author(s):  
Zhao Bo Meng ◽  
Teng Fei Zhao ◽  
Shi Cai Cui ◽  
Jie Jin
Keyword(s):  
Dynamic Response ◽  
Technical Specification ◽  
Time History ◽  
Response Analysis ◽  
Winkler Foundation ◽  
Analysis Model ◽  
Time Dynamic ◽  
Bell Tower ◽  
Vibration Loading ◽  
The Impact

Taking Xi’an Bell Tower and metro line 2 as research background, at first, according to the theory of Euler-Bernoulli beam in Winkler foundation, the analysis model of train-track-foundation system was established, and then, time-history curve of metro-induced loading acts on tunnel structure is obtained by using Matlab produce platform. Secondly, two-dimensional finite element model of the structure-soil-tunnel interaction model was established using ANSYS. Taken loading time delay into consideration for the first time, dynamic response law of the bell tower under the metro-vibration loading is obtained. Finally, the impact of metro line 2 on Xi’an Bell Tower was evaluated according to the Technical specification for protection of historic buildings against man-made vibration.

Sign in / Sign up

Export Citation Format

Share Document