No abstract

No abstract

No abstract

This article presents a progressive-failure analysis procedure to evaluate the performance of a building framework after it has been damaged by unexpected abnormal loading, such as an impact or blast load caused by a natural, accidental, or deliberate event, or as a result of human error in design and construction. To begin with, it is assumed that some type of short-duration abnormal loading has already caused some form of local damage to the structure. The residual load-carrying capacity of the remaining framework is then analyzed by incrementally applying the prevailing long-term loads and any impact debris loads, and progressively tracing the strength deterioration of the structure until either a globally stable state is reached or progressive collapse occurs for part or all of the structure. The computer-based procedure is based on the displacement method of analysis. The effect of both axial force and shear deformation on member and structure stiffness is accounted for in this article (Liu, 2004;Xu et al., 2004). The stiffness matrices for framework members account for elastic-plastic bending, shearing, and axial deformations, and are progressively updated under incrementally increasing loads through the use of degradation factors that characterize stiffness deterioration. The computational model allows the incremental analysis to proceed beyond loading levels at which structural instabilities occur, including the formation of plastic collapse mechanisms and the disengagement of members from the building superstructure. The progressive-failure analysis procedure is quite general and, with the appropriate choice of material constitutive model, may be applied to building frameworks of any type (concrete, steel, composite, etc.). Herein, a constitutive model for structural steel is adopted to account for elastic-plastic behavior under single or combined forces, and the progressive-failure analysis procedure is illustrated for two example planar steel moment frames.

This paper presents a finite element (FE) model developed using commercial FE software COMSOL to simulate the multiphysical process of pieozoelectric vibration energy harvesting (PVEH), involving the dynamic mechanical and electrical behaviours of piezoelectric macro fibre composite (MFC) on carbon fibre composite structures. The integration of MFC enables energy harvesting, sensing and actuation capabilities, with applications found in aerospace, automotive and renewable energy. There is an existing gap in the literature on modelling the dynamic response of PVEH in relation to real-world vibration data. Most simulations were either semi-analytical MATLAB models that are geometry unspecific, or basic FE simulations limited to sinusoidal analysis. However, the use of representative environment vibration data is crucial to predict practical behaviour for industrial development. Piezoelectric device physics involving solid mechanics and electrostatics were combined with electrical circuit defined in this FE model. The structure was dynamically excited by interpolated vibration data files, while orthotropic material properties for MFC and carbon fibre composite were individually defined for accuracy. The simulation results were validated by experiments with <10% deviation, providing confidence for the proposed multiphysical FE model to design and optimise PVEH smart composite structures.