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This paper reports the most recent developments concerning Generalized Beam Theory (GBT) formulations, and corresponding finite element implementations, for steel-concrete composite beams. These formulations are able to perform the following types of analysis: (i) materially nonlinear analysis, to calculate the beam load-displacement response, up to collapse, including steel plasticity, concrete cracking/crushing and shear lag effects, (ii) bifurcation (linear stability) analysis, to obtain local/distortional bifurcation loads and buckling mode shapes of beams subjected to negative (hogging) bending, accounting for shear lag and concrete cracking effects and (iii) long-term service analysis including creep, cracking and arbitrary cross-section deformation (which includes shear lag) effects. The potential (computational efficiency and accuracy) of the proposed GBT-based finite elements is illustrated through several numerical examples. For comparison purposes, results obtained with standard finite strip and shell/brick finite element models are provided.

An advanced shear lag model is developed to analyze the stress-shielding effect in injured muscle fiber by introducing the activation strain. The model considers three muscle fibers connected by the endomysium with the middle muscle fiber injured. Stress shielding describes the function of the lateral transmission of force in protecting the injured muscle fibers from being further injured by transferring force in the injured muscle fiber to its adjacent muscle fibers. Parameter studies demonstrate that the mechanical and geometrical properties of muscle fibers and the endomysium as well as the degree of injury can affect the stress-shielding effect. In conclusion, the model successfully demonstrates and captures, at least in a qualitative manner, the lateral transmission of force between an injured and a normal muscle fiber.

Utilization of corrugated steel plate as web in PC girder markedly separates functionality of flanges and web in resisting external force. The web responses mainly to resist for shearing force. However, by such separation, transferring of shearing force at the point of loading into the web seems to be retarded. The so–called shear lag phenomenon in the web is thought to occur. In this study, an extended beam theory is developed by considering that the web is shear deformable and satisfies Timoshenko beam theory. The governing equations and boundary conditions are derived by the variational principle. The calculated results based on the extended theory are then verified with those by the finite element analysis on a number of girder where a good agreement is found and the shear lag phenomenon in corrugated web is revealed.

In the recent years, piezoceramics (PZT) have found its niche in structural health monitoring. Commonly known as the electro-mechanical (EM) impedance method, this method utilizes the unique properties of the PZT to sense structural damage. Current modelling efforts with this technique has however, neglected the effects of the bond layer. Thus, the response prediction reliability and repeatability of the E/M admittance (the inverse of E/M Impedance) measurements between identical smart systems arise as an issue to be addressed. In this paper, a one-dimensional E/M impedance model accounting for shear lag between the PZT patch and the host structure is presented. Numerical analysis performed on a beam specimen has shown that the repeatability of measurements and the consistency of signatures between identical smart systems can be enhanced by the use of high modulus adhesives.