We study the steady-state and transient responses of a second-order elastic plate by implementing an asymptotic analysis three-dimensional equations with respect to two geometric characteristics seen as parameters: thickness inner material length. Depending on their ratio, four different models arise. Conditions under which Reissner–Mindlin kinematics may appear are discussed while influence cr...

The present study deals with the quasi-static and high strain rate characterization of Kevlar-129 based thermoplastic composites. Two different matrices, namely, Polypropylene (PP) Polyetherimide (PEI) were used to manufacture composite laminates. Quasi-static compression tests performed at rates 0.041 s ?1 0.045 . High using a split Hopkinson pressure bar apparatus within ranging from 2548 437...

In this study, we investigated the depth-dependent metabolic and structural responses of adult articular cartilage to large-strain, static, unconfined compression. Changes in cell biosynthetic activity and several morphometry-based structural parameters (cell density, cell volume fraction, cell surface-area density, mean cell surface area, and mean cell volume) were measured at eight sites repr...

The mechanical properties of the normal left ventricular wall during diastole were studied in 15 chronically instrumented, conscious dogs. Left ventricular minor and major axis diameters and equatorial wall thickness were measured with implanted pulse-transit ultrasonic dimension transducers. Left ventricular and pleural pressures were measured with high fidelity micromanometers. Circumferentia...

Tendons are important for optimal muscle force transfer to bone and play a key role in functional ability. Changes in tendon properties with aging could contribute to declines in physical function commonly associated with aging. We investigated the in vivo mechanical properties of the patellar tendon in 37 men and women [11 young (27 +/- 1 yr) and 26 old (65 +/- 1 yr)] using ultrasonography and...

The structural evolution of Pb(Mg(1/3)Nb(2/3))O(3) (PMN) has been reviewed in terms of characteristic temperatures, length scales and timescales, with a view to considering the overall relaxor behaviour from the perspectives of strain and elasticity. A conventional analysis of lattice parameter data in terms of spontaneous strain and strain/order parameter coupling shows that even though a norm...

Most tissues in the body are under mechanical tension, and while enzymes mediate many cellular and extracellular processes, the effects of mechanical forces on enzyme reactions in the native extracellular matrix (ECM) are not fully understood. We hypothesized that physiological levels of mechanical forces are capable of modifying the activity of collagenase, a key remodeling enzyme of the ECM. ...

The article is devoted to studying the stress-strain state (SSS) and assessing strength of Gissarak, Sokh, Pachkamar earth dams in a plane statement under action body forces hydrostatic pressure. A mathematical model, algorithm, computer program for structures are developed using Lagrange variational equation. finite element method was used problem solution. adequacy model accuracy algorithm we...

Several changes in the functional characteristics of fibronectin (FN) have been noted as cells become senescent in culture. In a previous report we showed that the steady state level of FN mRNA increases significantly during the process of in vitro cellular aging in a fibroblast strain. Because a phenomenon observed in one cell strain may not be the case in other cell strains, we extended the p...