A computer program is developed for the finite element nonlinear analysis of two-dimensional reinforced concrete structures under monotonie loading. The smeared-crack approach is used and the reinforcement is considered uniformly distributed within the element. An elastic work-hardening plastic stress-strain relationship with nonassociated flow rule is assumed for the concrete in compression an...

To understand how cells sense and adapt to mechanical stress, we applied tensional forces to magnetic microbeads bound to cell-surface integrin receptors and measured changes in bead displacement with sub-micrometer resolution using optical microscopy. Cells exhibited four types of mechanical responses: (1) an immediate viscoelastic response; (2) early adaptive behavior characterized by pulse-t...

We investigate with experiments the twist induced transverse buckling instabilities of an elastic sheet of length L, width W , and thickness t, that is clamped at two opposite ends while held under a tension T . Above a critical tension Tλ and critical twist angle ηtr, we find that the sheet buckles with a mode number n ≥ 1 transverse to the axis of twist. Three distinct buckling regimes charac...

nanocomposites made of carbon nanotube (cnt) bundles have attracted researchers’ attention due to their unusual properties such as: light weight, flexibility and stiffness.  in this paper, the effects of straight and rope-shaped bundles on nanocomposite effective mechanical properties are investigated.  first, fea models are created consisting of cnts with different shapes of straight and rope-...

Many fibers in biomaterials such as tendon, elastin, or silk feature a nonlinear stiffening behavior of the stress-strain relationship, where the rigidity of the material increases severely as the material is being stretched. Here we show that such nonlinear stiffening is beneficial for a fiber's ability to withstand cracks, leading to a flaw tolerant state in which stress concentrations around...

Vascular stiffening of the large arteries is a common feature of human aging. Increased aortic stiffness with age may contribute to pathological changes in the left ventricle and this can induce ventricular stiffening. Vascular-ventricular stiffening combined with abnormal arterial-cardiac interaction is considered an important pathophysiology of heart failure with a preserved ejection fraction...

The use of high-strength fibrous materials offers great potential to serve as the main reinforcement in flexural response lightweight concrete structures. Specifically, weft-knitted textile allows creating complex geometries (i.e. doubly curved or folded) and introducing straight inlays well spatial features such ribs within fabric enhance bond conditions between concrete. While evaluation unia...

The association between arterial stiffening and aging is well described and can be observed in almost all populations worldwide. A number of other cardiovascular risk factors including diabetes and cigarette smoking are also associated with increased large artery stiffness, often referred to as “premature arterial stiffening.” It is now apparent that the aortic pulse wave velocity (PWV), a meas...