Narrow Results

The influences of crack and delamination on the natural frequency and strain energy release rate of the laminated doubly curved shell structure are computed via a commercial finite element tool (ABAQUS). The effect of individual damages (crack and delamination) is modeled using the virtual crack closure technique (VCCT), considering the curvature effect. Initially, the model validity is established by comparing the results with the available results in the open domain. Additionally, the model validity has been verified via in-house experimentation for frequency responses. Further, the natural frequency and strain energy release rate (SERR) have been calculated for the structure to examine the influences of the individual or combined effect of damages by varying the design-dependent input geometrical parameters. The inclusive characteristics of the current model in conjunction with geometrical configurations are summarized for subsequent references.

It has been observed by performing simple and diagonal compression tests of cob wallettes that the structural behavior of cob is highly nonlinear. This paper presents the results obtained of the simulation of cob’s nonlinear monotonic behavior using two well-known finite element commercial packages. Pros and cons of different available constitutive material models are identified and discussed. Concrete (CONCR) and Concrete Damaged Plasticity (CDP) are considered as the constitutive material models that provide the more satisfactory results reproducing cob’s nonlinear monotonic behavior when using ANSYS and ABAQUS, respectively.

Dissipative processes such as viscoelasticity and current leakage are known to affect the electromechanical performance of dielectric elastomers. In this work, we describe a constitutive theory that couples electrostatics, large deformation, viscoelasticity and current leakage. We also implement this model in a commercial finite element solver ABAQUS by developing new user-defined elements. The method is used to study the effect of viscoelasticity and current leakage on the behavior of dielectric elastomers. Our finite element implementation will serve as a simulation platform to guide the design of practical dielectric elastomer transducers.

The free vibration frequency responses of the laminated composite structure with a cut-out of variable shapes (square/circular/elliptical), position (center/eccentric) and orientation (parallel/inclined) are investigated for the first time in this research including geometrical shapes. The eigenvalues are obtained computationally for the cut-out borne structure via a linear isoparametric finite element model of the composite structure in association with cubic-order of displacement kinematics. Also, a coupled code is prepared in MATLAB environment by joining the higher-order formulation and the simulation model (ABAQUS) to achieve the generic form to investigate the influential cut-out parameter (shape, size and position) on their eigenvalues. Further, a series of experimentations are carried out using the cut-out borne composite panel and compared with the computational frequency, including the experimental properties. Finally, the key behavior is surveyed through different kinds of numerical examples for various design constraint parameters including the cut-out relevant factors (shape, position and orientation) to show the subsequent inclusiveness of the proposed model.