Cardiac muscle stiffness can potentially be estimated non-invasively with shear wave elastography. Shear waves are present on the septal wall after mitral and aortic valve closure, thus providing an opportunity to assess stiffness in early systole and early diastole. We report on the shear wave recordings of 22 minipigs with high-frame-rate echocardiography. The waves were captured with 4000 fr...

This paper provides an overview of recent results for relay-delay systems. In a first section, simple examples illustrate the problems induced by delays in the synthesis of sliding mode controllers. Then, a brief overview of the existing results shows the present advances and limits in this domain. The last parts of the paper are devoted to new results: first, for systems with state delay, then...

In this paper, an efficient technique is presented for static analysis of tall buildings with combined tube-in-tube and outrigger-belt truss system while considering shear lag effects. In the process of replacing the discrete structure with an elastically equivalent continuous one, the structure is modeled as two parallel cantilevered flexural-shear beams that are constrained at the outrigger-b...

This study investigates the accuracy and reliability of a novel handheld indentation system designed to ascertain the dynamic biomechanical properties of articular cartilage. A series of standard elastomers were assessed with both the handheld indentation system and a bench-top dynamic indentation system to assess the accuracy of the instrument. Interoperator and intraoperator experiments were ...

In this paper, we develop a shear-lag model and an in ̄uence superposition technique to quickly compute the stresses and displacements in 2D unidirectional ®ber composites in response to multiple ®ber and matrix breaks. Unlike previous techniques, both the ®ber and matrix are able to sustain axial load, and the governing shear-lag equations are derived based on the principle of virtual work and ...

Out-of-plane compression tests were conducted on six grades of ultra high molecular weight polyethylene fibre composites (Dyneema) with varying grades of fibre and matrix, ply thickness, and ply stacking sequence. The composites with a [01/901] lay-up had an out-of-plane compressive strength that was dictated by in-plane tensile fibre fracture. By contrast, the out-of-plane compressive strength...

Bioinspired discontinuous nanolaminate design becomes an efficient way to mitigate the strength-ductility tradeoff in brittle materials via arresting the crack at the interface followed by controllable interface failure. The analytical solution and numerical simulation based on the nonlinear shear-lag model indicates that propagation of the interface failure can be unstable or stable when the i...