Due to the mismatch of mechanical properties in composite laminates, propagation of delami-nation is considered as a severe damage mechanism in beams with various lay-up configurations. Delamination can be generated due to matrix cracking propagation or it can also be initiated due to the manufacturing process before using composite beams. Using a micromechanics model, this study is aimed to in...

in this article the general non-symmetric parametric form of the incremental secant stiffness matrix for nonlinear analysis of solids have been investigated to present a semi analytical sensitivity analysis approach for geometric nonlinear shape optimization. to approach this aim the analytical formulas of secant stiffness matrix are presented. the models were validated and used to perform inve...

This paper presents the effects of different amounts of reclaimed asphalt on fatigue life of asphalt mixtures. Central composite method was used to design of experiments based on response surface method (RSM). Binder type (Pen 60/70 and Pen 85/100), reclaimed asphalt pavement (RAP) content (25, 50 and 75%) and loading strain (150, 250 and 350 micro strain) were selected as independent variables...

left atrial (la) distension has been demonstrated to be linked with aortic stiffness in different patient populations. three-dimensional (3d) speckle-tracking echocardiography (ste) seems to be a promising tool for volumetric and functional evaluation of the la. the aim of the present study was to determine whether correlations exist between 3dste-derived la volume-based and strain parameter...

This paper describes triaxial compression tests conducted to determine the effect of fiber inclusion on stiffness and deformation characteristics of sand-gravel mixtures. Tested soil was a mixture of Babolsar sand from the shores of the Caspian Sea and Karaj River gravel. Portland cement was used as the cementing agent and fibers 12mm in length and 0.023mm in diameter at 0%, 0.5% and 1.0% were ...

AIMS Elastic properties of large arteries have been shown to deteriorate with age and in the presence of atherosclerotic vascular disease. In this study, the performance of ultrasonographic strain measurements was compared with conventional measures of vascular stiffness in the detection of age-dependent differences in the elastic properties of the common carotid artery (CCA). METHODS AND RES...

The free vibration characteristics of a dual split torque transmission are studied in this work. A transversetorsional coupling dynamic model is developed using lumped parameter method. The natural frequencies and mode shapes are calculated by solving the eigenvalue problem of the differential equations of motion. The vibration modes of the system are classified into translational mode and rota...

Stiffness matrix of the four-node quadrilateral plane stress element is decomposed into normal and shear components. A computer program is developed to obtain the straining modes using adequate and reduced integration. Then a solution for the problem of mixing straining modes is found. Accuracy of the computer program is validated by a closed-form stiffness matrix, derived for the plane rectang...

Formation of bacterial colonies as biofilm on the surface/interface of various objects has the potential to impact not only human health and disease but also energy and environmental considerations. Biofilms can be regarded as soft materials, and comprehension of their shear response to external forces is a key element to the fundamental understanding. A mesoscale model has been presented in th...