Bending, buckling and free vibration of laminated composite and sandwich beams: A critical review of literature

Finite element analysis of fastening and joining: A bibliography (1990–2002)

This paper throws a small "wet blanket" on the hot topic of GPGPU acceleration, based on experience analyzing and tuning both multithreaded CPU and GPU implementations of three computations in scientific computing. These computations--(a) iterative sparse linear solvers; (b) sparse Cholesky factorization; and (c) the fast multipole method--exhibit complex behavior and vary in computational intensity and memory reference irregularity. In each case, algorithmic analysis and prior work might lead us to conclude that an idealized GPU can deliver better performance, but we find that for at least equal-effort CPU tuning and consideration of realistic workloads and calling-contexts, we can with two modern quad-core CPU sockets roughly match one or two GPUs in performance.

Our conclusions are not intended to dampen interest in GPU acceleration; on the contrary, they should do the opposite: they partially illuminate the boundary between CPU and GPU performance, and ask architects to consider application contexts in the design of future coupled on-die CPU/GPU processors.

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On the limits of GPU acceleration

Seismic response of secondary systems

This paper deals with the accurate evaluation of complete three-dimensional (3D) stress fields in beam structures with compact and bridge-like sections. A refined beam finite-element (FE) formulation is employed, which permits any-order expansions for the three displacement components over the section domain by means of the Carrera Unified Formulation (CUF). Classical (Euler-Bernoulli and Timoshenko) beam theories are considered as particular cases. Comparisons with 3D solid FE analyses are provided. End effects caused by the boundary conditions are investigated. Bending and torsional loadings are considered. The proposed formulation has shown its capability of leading to quasi-3D stress fields over the beam domain. Higher-order beam theories are necessary for the case of bridge-like sections. Various theories are also compared in terms of shear correction factors on the basis of definitions found in the open literature. It has been confirmed that different theories could lead to very different values of shear correction factors, the accuracy of which is subordinate to a great extent to the section geometries and loading conditions. However, an accurate evaluation of shear correction factors is obtained by means of the present higher-order theories.

Performance of CUF Approach to Analyze the Structural Behavior of Slender Bodies

A new finite element for the analysis of thin-walled open beams with an arbitrary cross section is presented. Combining Timoshenko beam theory and Vlasov thin-walled beam theory, the derived element includes both flexural shear deformations and warping deformations caused by the bimoment. By adopting an orthogonal Cartesian co-ordinate system, one can obviate the ad hoc introduction of St. Venant stiffness. The derived block stiffness matrix is comparable but more general than the one given by earlier researchers. The versatility and accuracy of the new element are demonstrated by comparing the numerical results with the classical solutions or other numerical results available in the literature. © 1998 John Wiley & Sons, Ltd.

A shear-flexible element with warping for thin-walled open beams

Shear-flexible thin-walled element for composite I-beams

A finite element model is presented for the lateral buckling analysis of beams and frames having a plane of symmetry in the midsurface of the web. In-plane and out-of-plane behaviors are assumed to be uncoupled. Lower order displacement assumptions are used for the geometric stiffness matrices than for the conventional stiffness matrices. Specific applications of the two-dimensional model are demonstrated for the analysis of structures having I-section members. The proposed model for such members accounts for the interaction between the local and the overall buckling phenomena. The web is allowed to distort. Realistic representation of I-section structures with tapered members, deep sections, complex joints, web stiffeners, and various elastic restraints can be made. Effects of stress concentrations at the joints and under the loads are considered. Three numerical examples: (1)A beam with a stiffener; (2)a gable frame; and (3)a deep highway bridge girder, are presented to illustrate the applicability of the model.

Lateral and Local Buckling of Beams and Frames

Precast concrete panels form attractive facades for steel frame buildings and are generally regarded as non-structural by structural engineers. However, panels have been found to add lateral stiffness until their capacity or that of their connections is exceeded. Consequently, the computed dynamic response based on a model of the structural framing alone may be quite different from that experienced by the actual structure.



As a case study, the influence of precast concrete panels on lateral and torsional stiffness of a 25-storey building was investigated. The effect of cladding on dynamic properties and linear seismic response was explored by varying panel stiffness. Cladding stiffness was added to the bare frame model until analytical frequency values matched vibration test results. Then, using the cladding stiffness values obtained, an accidental eccentricity between centres of mass and rigidity at each floor level was imposed and linear seismic response computed. Torsional response effects were increased substantially. Finally, a modified cladding panel connection was developed based on previously-reported studies for panelized construction. The influence of the proposed connection on overall structural response was determined for different ground motion inputs.

Cladding influence on dynamics response of tall buildings

Offshore structures are generally constructed as frameworks of tubular members. The tubular joints should be designed to allow the full post yield or post buckled capacity of the members. However, design guidelines for ultimate strength capacity of these joints are based exclusively upon compilations of test data for simple configurations under simple loading conditions. A methodology based upon the finite element method is presented for analytically predicting the ultimate strength of arbitrary tubular joints. Eight node, isoparametric, curved shell elements were used for the majority of the tubular joint model. Twenty node, isoparametric, solid elements were used to capture the three‐dimensional stress state at the shell intersection while fifteen node, isoparametric, wedge elements modelled the weld profile. Solid‐shell transition elements provided the connection between the three‐dimensional solid elements and the surface based shell elements. Non‐linearities were included via an elastoplastic material model with isotropic strain hardening and the updated Lagrangian approach for finite deflections and rotations. Several experimental tubular joint analyses were reproduced to validate the analytical procedure. Non‐linear finite element analysis was shown to be a practical approach for the evaluation and extension of current design procedures for tubular joints.

Kenneth M. Will

Papers

A shear-flexible element with warping for thin-walled open beams

Shear-flexible thin-walled element for composite I-beams

Lateral and Local Buckling of Beams and Frames

Cladding influence on dynamics response of tall buildings

A finite element technique for the ultimate strength analysis of tubular joints