A frequency domain dynamic analysis is needed to obtain the response of structures constructed on a system of base isolators on flexible soil when subjected to earthquake ground motion. In such systems, the lateral stiffness of the base isolators is so small, compared to the structural stiffness, that in an earthquake attack the fundamental vibration mode dominates the response. With this in mi...

This paper describes the experimental studies of vertical dynamic stiffness of single piles subjected to small amplitude of vibrations with constant dynamic load. The test results were correlated with the static load test results that had been carried out on the same piles. The ratio of dynamic to static stiffness mainly falls between 1.2-1.4. The dynamic stiffness measurements were compared wi...

Matrix stiffness strongly influences growth, differentiation and function of adherent cells. On the macro scale the stiffness of tissues and organs within the human body span several orders of magnitude. Much less is known about how stiffness varies spatially within tissues, and what the scope and spatial scale of stiffness changes are in disease processes that result in tissue remodeling. To b...

Variable stiffness structures that enable a wide range of efficient load-bearing and dexterous activity are ubiquitous in mammalian musculoskeletal systems but are rare in engineered systems because of their complexity, power, and cost. We present a new negative stiffness-based load-bearing structure with dynamically tunable stiffness. Negative stiffness, traditionally used to achieve novel res...

-Stiffness modulation scheme for a robotic driving system with redundant actuation was investigated in this paper. The dynamic and the stiffness models of a simple system having one link and two prismatic actuators were derived and employed for computational simulations of dynamic response to an initial disturbance. Several combinations with different types of elastic elements were applied to t...

Aggravated behaviors of hepatocellular carcinoma (HCC) will occur after inadequate thermal ablation. However, its underlying mechanisms are not fully understood. Here, we assessed whether the increased matrix stiffness after thermal ablation could promote the progression of residual HCC. Heat-treated residual HCC cells were cultured on tailorable 3D gel with different matrix stiffness, simulati...

Many structural components can be regarded as waveguides. They are uniform in one direction so that the cross section of the waveguide has the same physical and geometric properties at all points along the axis of the waveguide. In this paper a method is presented to calculate the forced response of such a structure using a combination of wave and finite element (FE) approaches. The method invo...

The microtubule organizing center (MTOC) frequently polarizes to a position in front of the nucleus during cell migration, but recent work has shown conflicting evidence for MTOC location in migratory polarized cells. Here, we show that subcellular localization of the MTOC is modulated by extracellular matrix stiffness. In scratch wound assays as well as single cell migration of mesenchymal ste...

A finite element numerical method is investigated for fractional order elliptic boundary value problems with homogeneous Dirichlet type boundary conditions. It is pointed out that an appropriate stiffness matrix can be obtained by taking the prescribed fractional power of the stiffness matrix corresponding to the non-fractional elliptic operators. It is proved that this approach, which is also ...