Abstract
The problem of the elastic buckling of a cylindrical liquid-storage tank subject to horizontal earthquake loading is considered. An equivalent static loading is used to represent the dynamic effect. A theoretical solution based on the nonlinear Flugge shell equations is developed, and numerical results are found using the new differential quadrature method. A second solution is obtained using the finite element package ADINA. A major motivation of the study was to show that the new method can serve to verify finite element solutions for cylindrical shell buckling problems. For this purpose the paper concludes with a comparison of buckling results for a number of cases covering a wide range in tank geometry.
Key Words
buckling; tanks; earthquake loading; differential quadrature method; finite element method.
Address
Department of Mechanical Engineering University of Ottawa Ottawa, Canada K1N 6N5
Abstract
In this paper, the behaviour of axially loaded partially encased composite columns made with light welded H steel shapes is examined using ABAQUS finite element modelling. The results of the numerical simulations are compared to the response observed in previous experimental studies on that column system. The steel shape of the specimens has transverse links attached to the flanges to improve its localrnbuckling capacity and concrete is poured between the flanges only. The test specimens included 14 stubcolumns with a square cross section ranging from 300 mm to 600 mm in depth. The transverse link spacing varied from 0.5 to 1 times the depth and the width-to-thickness ratio of the flanges ranged from 23 to 35. Thernnumerical model accounted for nonlinear stress-strain behaviour of materials, residual stresses in the steel shape, initial local imperfections of the flanges, and allowed for large rotations in the solution. A Riks displacement controlled strategy was used to carry out the analysis. Plastic analyses on the composite modelsrnreproduced accurately the capacity of the specimens, the failure mode, the axial strain at peak load, the transverse stresses in the web, and the axial stresses in the transverse links. The influence of applying a typical construction loading sequence could also be reproduced numerically. A design equation is proposed torndetermine the axial capacity of this type of column.
Key Words
composite column; built-up steel shape; local buckling; finite element models; materials
Address
Department of Civil, Geological, and Mining Engineering, Ecole Polytechnique, Montreal, H3C 3A7, Canada
Abstract
Elasticity solutions to the boundary-value problems of dynamic response under transverse asymmetric load of cross-ply shallow cylindrical panels are presented. The shell panel is simply supported along all four sides and has finite length. The highly coupled partial differential equations are reduced to ordinary differential equations with constant coefficients by means of trigonometric function expansion in the circumferential and axial directions. The resulting ordinary differential equations are solved by Galerkin finite element method. Numerical examples are presented for two (0/90 deg.) and three (0/90/0 deg.) laminations under dynamic loading.
Key Words
elastictiy; panel; shallow; dynamic; composite.
Address
Department of Mechanical Engineering, Amirkabir University of Technology, Iran
Abstract
This paper describes the buckling phenomenon of a tubular truss with unsupported lengthrnthrough a full-scale test and presents a practical computational method for the design of the trusses allowingrnfor the contribution of torsional stiffness against buckling, of which the effect has never been consideredrnpreviously by others. The current practice for the design of a planar truss has largely been based on the linearrnelastic approach which cannot allow for the contribution of torsional stiffness and tension members in arnstructural system against buckling. The over-simplified analytical technique is unable to provide a realisticrnand an economical design to a structure. In this paper the stability theory is applied to the second-orderrnanalysis and design of the structural form, with detailed allowance for the instability and second-order effectsrnin compliance with design code requirements. Finally, the paper demonstrates the application of the proposedrnmethod to the stability design of a commonly adopted truss system used in support of glass panels in whichrnlateral bracing members are highly undesirable for economical and aesthetic reasons.
Address
Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hong KongrnBuildings Department, Hong Kong SAR Government, Hong KongrnDepartment of Civil Engineering, University of Queensland, Australia
Abstract
An analytical procedure based on the transfer matrix method to estimate not only the naturalrnfrequencies but also vibration mode shapes of the thin-walled members composed of interconnectedrncylindrical shell panels is presented. The transfer matrix is derived from the differential equations for therncylindrical shell panels. The point matrix relating the state vectors between consecutive shell panels are usedrnto allow the transfer procedures over the cross section of the members. As a result, the interactions betweenrnthe shell panels of the cross sections of the members can be considered. Although the transfer matrix methodrnis naturally a solution procedure for the one-dimensional problems, this method is well applied to thin-walledrnmembers by introducing the trigonometric series into the governing equations of the problem. The naturalrnfrequencies and vibration mode shapes of the thin-walled members composed of number of interconnectedrncylindrical shell panels are observed in this analysis. In addition, the effects of the number of shell panels onrnthe natural frequencies and vibration mode shapes are also examined.rn
Key Words
natural frequency; mode shape; thin-walled member; cylindrical shell panel; transfer matrix
Address
Department of Civil and Environmental Engineering, Ehime University,rnMatsuyama 790-8577, JapanrnProfessor, Tokuyama Technical College, Tokuyama 745-8585, Japan
