A new method is presented for identifying the local stiffness of a structure from vibration test data. The method is based on a projection of the experimentally measured flexibility matrix onto the strain energy distribution in local elements or regional superelements. Using both a presumed connectivity and a presumed strain energy distribution pattern, the method forms a well-determined linear...

A novel element with arbitrary domain shape by using decoupled scaled boundary finite element (DSBFEM) is proposed for eigenvalue analysis of 2D vibrating rods with different boundary conditions. Within the proposed element scheme, the mode shapes of vibrating rods with variable boundary conditions are modelled and results are plotted. All possible conditions for the rods ends are incorporated ...

curls and curves of a shell interweave its various strain modes and link them together. this interactional behavior has yet frustrated all attempts for the construction of shell templates, which needs for an individual element test in traditional approaches. such a test fails to work for shell elements and must be reconstructed. in this paper, it is tried to study shell interactional behavior a...

An interaction integral method for evaluating mixed-mode stress intensity factors (SIFs) for two dimensional crack problems using NURBS-based isogeometric analysis method is investigated. The interaction integral method is based on the path independent J-integral. By introducing a known auxiliary field solution, the mixed-mode SIFs are calculated simultaneously. Among features of B-spline basis...

A = aerodynamic stiffness matrix C = speed of sound E = complex Fourier matrix f , F = physical and modal forces h = height of stream tube j = imaginary unit K, M = stiffness and mass matrices NB = number of blades P, Q = modal transformation matrices p = flow pressure Q = flow mass flux at the boundary q = generalized (modal) coordinate s = distance along the boundary T = period of flow unstea...

for the nonlinear analysis of structures using the well known newton-raphson method, the tangent stiffness matrices of the elements must be constructed in each iteration. due to the high expense required to find the exact tangent stiffness matrices, researchers have developed novel innovations into the newton-raphson method to reduce the cost and time required by the analysis. in this paper, a ...

During consolidation process of saturated cohesive soil the soil stiffness increases. Increase of the effective stress due to dissipation of excess pore pressure causes additional stiffness of soil mass. This phenomenon has a very important effect on the behavior of saturated cohesive soils during dynamic loading. In the current investigation the changes in maximum shear modulus. Gmax and dampi...

Hygrothermal analysis of laminated composite plates has been done by using an efficient higher order shear deformation theory. The stress field derived from hygrothermal fields must be consistent with total strain field in this type of analysis. In the present formulation, the plate model has been implemented with a computationally efficient C0 finite element developed by using consistent strai...

Polyurethane/zeolite 13X nanocomposite films were fabricated using solution casting method. The synthesized nanocomposite films were structurally characterized using SEM, TGA and tensile analysis. SEM images showed appropriate distribution of nanocrystalline zeolite particles within polyurethane matrix. Better thermal stability of nanocomposite films in comparison to neat polyurethane was shown...

Polyurethane/zeolite 13X nanocomposite films were fabricated using solution casting method. The synthesized nanocomposite films were structurally characterized using SEM, TGA and tensile analysis. SEM images showed appropriate distribution of nanocrystalline zeolite particles within polyurethane matrix. Better thermal stability of nanocomposite films in comparison to neat polyurethane was shown...