This paper analyzes the adequacy of shell models for predicting stresses and strains in thick-walled tubes subjected to detonation loads. Of particular interest are the large axial strains which are produced at the inner and outer surfaces of the tube due to bending along the tube axis. First, comparisons between simple shell theory and a static finite element model are used to show that the ax...

in this research, using the modified compression field theory (mcft), a new truss based model is proposed to predict the behavior of reinforced concrete coupling beams with diagonal reinforcement. the model is able to consider the effects of shear and axial forces and bending moment, simultaneously. the proposed model includes a nonlinear shear spring, an axial spring, two inclined truss member...

Coronary artery bypass grafts (CABG) are widely studied with respect to hemodynamic conditions which play important role in presence of a restenosis. However, papers which concern with constitutive modeling of CABG are lacking in the literature. The purpose of this study is to find a constitutive model for CABG tissue. A sample of the CABG obtained within an autopsy underwent an inflation–exten...

In this paper, the nonlinear vibration analysis of a thin cylindrical shell made of Functionally Graded Material (FGM) resting on a nonlinear viscoelastic foundation under compressive axial and lateral loads is studied. Nonlinear governing coupled partial differential equations of motions (PDEs) for cylindrical shell are derived using improved Donnell shell theory. The equations of motions (EOM...

In this paper, the law of radial envelope forming (REF) thin wall cylinder with vertical reinforcements is studied by finite element numerical simulation. First, a model for REF established using Deform-3D software. Then, evolution and distribution strain metal flow velocity during are analyzed, growth reinforcement analyzed in detail. The results show that compression strain, circumferential t...

A procedure for efficient three-dimensional nonlinear time-history analysis of steel framed buildings is derived. It incorporates two types of nonlinear beam elements—the plastic hinge type and the elastofiber type—and nonlinear panel zone elements to model yielding and strain-hardening in moment-frames. Floors and roofs of buildings are modeled using 4-node elastic diaphragm elements. The proc...

This paper explores the vibration damping properties of thermal barrier coatings (TBCs) containing thin plastically deformable metallic layers embedded in an elastic ceramic matrix. We develop an elastic–plastic dynamical model to study how work hardening, yield strain, and elastic modulus of the metal affect the macroscopic damping behavior of the coating. Finite element (FE) simulations valid...

Ultrasound elastography produces strain images of compliant tissues under quasi-static compression. In axial-shear strain elastography, the local axial-shear strain resulting from application of quasi-static axial compression to an inhomogeneous material is imaged. The overall hypothesis of this work is that the pattern of axial-shear strain distribution around the inclusion/background interfac...

In axial-shear strain elastography, the local axial-shear strain resulting from the application of quasi-static axial compression to an inhomogeneous material is imaged. In this paper, we investigated the image quality of the axial-shear strain estimates in terms of the signal-to-noise ratio (SNR(asse)) and contrast-to-noise ratio (CNR(asse)) using simulations and experiments. Specifically, we ...

The only effective method of fiber Bragg grating (FBG) strain modulation has been by changing the distance between its two fixed ends. We demonstrate an alternative that is more sensitive to force based on the nonlinear amplification relationship between a transverse force applied to a stretched string and its induced axial force. It may improve the sensitivity and size of an FBG force sensor, ...