检索结果-南通市图书馆

Acta Mechanica Solida Sinica 2016年第6期29卷 577-595页

作者： Nian Yang Luyun Chen Hong Yi Yong Liu State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Ship Scientific Research Center of China Shanghai Branch

Most existing studies on the vibration analysis of cylindrical shells with structural stress are limited to uniform stress distribution. However, non-uniform stress distributions are encountered in many engineering applications. In this study, a unified solution for the vibration analysis of cylindrical shells with a general stress distribution is presented using the Fliigge shell theory and modal orthogonality simplification. The obtained analytical solution can be applied to a structure with arbitrary distributed stress, thus it has a wider range of applications than previous methods. The accuracy and advantage of the proposed method are validated by comparing with the finite element method results.

关键词： free vibration cylindrical shells structural stress

NONLINEAR INTERNAL RESONANCE OF FUNCTIONALLY GRADED cylindrical shells USING THE HAMILTONIAN DYNAMICS

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2014年第6期27卷 635-647页

作者： Changcheng Du Yinghui Li School of Mechatronic Engineering Southwest Petroleum University School of Mechanics and Engineering Southwest Jiaotong University

Internal resonance in nonlinear vibration of functionally graded （FG） circular cylin- drical shells in thermal environment is studied using the Hamiltonian dynamics formulation. The material properties are considered to be temperature-dependent. Based on the Karman-Donnell＇s nonlinear shell theory, the kinetic and potential energy of FG cylindrical thin shells are formu- lated. The primary target is to investigate the two-mode internal resonance, which is triggered by geometric and material parameters of shells. Following a secular perturbation procedure, the underlying dynamic characteristics of the two-mode interactions in both exact and near resonance cases are fully discussed. It is revealed that the system will undergo a bifurcation in near resonance case, which induces the dynamic response at high energy level being distinct from the motion at low energy level. The effects of temperature and volume fractions of composition on the exact resonance condition and bifurcation characteristics of FG cylindrical shells are also investigated.

关键词： functionally graded material cylindrical shells nonlinear vibration internal res-onance Hamiltonian dynamics

On the higher-order thermal vibrations of FG saturated porous cylindrical micro-shells integrated with nanocomposite skins in viscoelastic medium

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第8期18卷 1416-1434页

作者： Zeinab Soleimani-Javid Ehsan Arshid Saeed Amir Mahdi Bodaghi Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashanIran Department of Engineering School of Science and TechnologyNottingham Trent UniversityNottinghamNG118NSUK

Since the multi-layered structures are widely used nowadays, and due to interesting applications of cylindrical shells, this study is dedicated to analyzing free vibrational behaviors of functionally graded saturated porous micro cylindrical shells with two nanocomposite skins. Based on Biot's assumptions, constitutive relations for the core are presented and effective properties of the skins are determined via the rule of mixture. A sinusoidal theory is used to capture the shear deformation effects, and to account for the scale effects, the modified couple stress theory is employed which suggests a material length-scale parameter for predicting the results in small-dimension. With the aid of extended form of Hamilton's principle for dynamic systems, differential equations of motion are extracted. Fourier series functions are used to obtain natural frequencies and after validating them, a set of parametric studies are carried out. The results show the significant effects of porosity and Skempton coefficient, pores placement patterns, CNTs addition and distribution patterns, temperature variations, material length-scale parameter and viscoelastic medium on the natural frequencies of the microstructure. The outcomes of this work could be used to design and manufacture more reliable micro cylindrical structures in thermo-dynamical environments.

关键词： Vibration analysis cylindrical shells Saturate porous materials Nanocomposite materials Carbon nanotubes Sinusoidal shear deformation theory Viscoelastic medium

The Influence of Residual Stress on Plastic Buckling of cylindrical shells

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 1994年第2期9卷 135-144页

作者： Wu Lianyuan Hu Gangyi Professor, Shanghai Jiaotong University, Shanghai 200030 Engineer, Wuhan Ship Development & Design Institute, Wuhan 430064

-This paper adopts approximate formulas for residual stresses caused by cold bending for plates with stress-strain curve form a = K n. A typical distribution of the longitudinal residual stress due to welding is also assumed. The effects of residual stress due to cold bending and welding on plastic buckling of axially compressed cylindrical shells are studied by the finite element method.

关键词： residual stress cylindrical shells plastic buckling

Numerical Simulation and Dynamic Fracture Criteria of Thin cylindrical shells under Inner Explosive Loading

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2000年第1期5卷 13-17页

作者：高重阳施惠基姚振汉王晓华白春华 Department of Engineering Mechanics Tsinghua University Beijing 100084 China Department of Mechanical Engineering Beijing Institute of Technology Beijing 100081 China

An FAE (Fuel Air Explosives) device is used to develop a numerical and theoretical analysis of a thin cylindrical shell with inner explosive loading. The dynamic fracture process is simulated numerically in the DYNA3D program using the finite element method. The material’s dynamic properties are described by a strain hardening viscoplastic constitution. A damage variable is introduced in the determination of the dynamic fracture criterion. Final rupture of structure is decided by a rupture strain criterion which is deduced in terms of a critical damage variable. The numerical results have been compared with theoretical solutions.

关键词： numerical simulation cylindrical shells dynamic fracture criteria explosive loading damage 

THE DYNAMIC BUCKLING OF AN ORTHOTROPIC cylindrical THIN SHELL UNDER TORSION VARYING AS A POWER FUNCTION OF TIME

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2003年第1期16卷 81-87页

作者： Sofiyev Abdullah A1 Ay Zeki A1 Sofuyev Ali A2 Department of Civil Engineering Suleyman Demirel University Isparta Turkey Kazakh Filial Tech. Sci. Department Gence Pedagogic University Kazakh Azerbaijan

The subject of this investigation is to study the buckling of orthotropic cylindrical thin shells under torsion, which is a power function of time. The dynamic stability and compatibility equations are obtained first. These equations are subsequently reduced to a time dependent differential equation with variable coefficient by using Galerkin's method. Finally, the critical dynamic and static loading, the corresponding wave numbers, the dynamic factors, critical time and critical impulse are found analytically by applying the Ritz type variational method. Using those results, the effects of the variations of the power of time in the torsion load expression, of the loading parameter, the ratio of the Young's moduli and the ratio of the radius to thickness on the critical parameters are studied numerically. It is observed that these factors have appreciable effects on the critical parameters of the problem in the heading.

关键词： dynamic buckling cylindrical shells torsion dynamic critical load dynamic factor critical impulse

THE ELASTO-PLASTIC ANALYSIS OF REINFORCED CONCRETE shells BY RIGID ELEMENT METHOD

在线全文

学校读者我要写书评

暂无评论

THE ELASTO-PLASTIC ANALYSIS OF REINFORCED CONCRETE SHELLS BY...