Starting from the definition of a stiffness matrix, the authors present a new formulation of the Cartesian stiffness matrix of parallel mechanisms. The proposed formulation is more general than any other stiffness matrix found in the literature since it can take into account the stiffness of the passive joints, it can consider additional compliances in the joints or in the links and it remains ...

This study focuses on achieving high stiffness/strength and good FR characteristic of nylon 66/MCA/NC nanocomposites, prepared via melt compounding by twin screw extruder. A synergistic effect of flame retardant systems based on melamine cyanurate and zinc borate on the flammability and mechanical behaviours of crysnanoclay reinforced nylon 66 nanocomposites have been reported. Mechanical test ...

The main objective of this study is to reduce optimal vibration suppression of Timoshenko beam under non-periodic step and impulse inputs. Cantilever beam was modeled by Timoshenko theory and finite element numerical method. Stiffness (K), mass (M), and damping (C) matrices are extracted. Then, in order to control structure vibration, piezoelectric patches were used due to simultaneous dual beh...

Various kinds of finite elements are proposed and employed for one-dimensional wavefield simulations, each of which has their own capabilities and disadvantages. This paper deals with structural similarities and differences that arise at the element level, by the use of reduced forms of mass and stiffness matrices. General parameterized forms are then developed for mass and stiffness matrices o...

This paper presents a generalized numerical method to evaluate element stiffness matrices needed for the free vibration and stability analyses of non-prismatic columns resting on one- or two-parameter elastic foundations and subjected to variable axial load. For this purpose, power series approximation is used to solve the fourth–order differential equation of non-prismatic columns with v...

BACKGROUND Topography, stiffness, and composition of biomaterials play a crucial role in cell behaviors. In this study, we have investigated biochemical (gene markers), biophysical (roughness), and biomechanical (stiffness) changes during the osteogenic differentiation of preosteoblasts on gelatin matrices. RESULTS Our results demonstrate that gelatin matrices offer a favorable microenvironme...

The role of a stiffening extra-cellular matrix (ECM) in cancer progression is documented but poorly understood. Here we use a conditioning protocol to test the role of nonmuscle myosin II isoforms in cell mediated ECM arrangement using collagen constructs seeded with breast cancer cells expressing shRNA targeted to either the IIA or IIB heavy chain isoform. While there are several methods avail...

The paper presents an approach for the identification of elasto-static parameters of a robotic manipulator using the virtual experiments in a CAD environment. It is based on the numerical processing of the data extracted from the finite element analysis results, which are obtained for isolated manipulator links. This approach allows to obtain the desired stiffness matrices taking into account t...