The lateral vibration of cracked isotropic thick beams is investigated. Generally, the analysis beam based on line elements can be undertaken using either Timoshenko theory or a third order (TSDT) such as Reddy theory. TSDT superior to theory, it eliminates need for shear correction coefficient. However, there no available solution which main focus this paper. investigated divided into several ...

In order to realize the accurate prediction of vibration fatigue life beam in service, a loose coupling analysis method is proposed carry out with an initial crack. modal analysis, crack segment replaced torsion spring, and damping loss factor introduced by complex modulus elasticity; for simply supported beam, inherent characteristic equation cracked derived. interaction between crack’s growth...

The prediction of the service life of concrete materials is difficult, mainly because of their complex heterogeneous microstructure and their random nature. Studying the presence of cracks in concrete and their effect on chloride transport and binding properties is of great interest in civil engineering. Cracks with different widths and depths will reduce the effective cover thickness and accel...

The objective of this paper is to control the phase shifting by applying a bias DC voltage and changing the mechanical characteristics in electrostatically-actuated micro-beams. This problem can be more useful in the design of micro-phase shifters, which has not generally been investigated their mechanical behavior. By presenting a mathematical modeling, Galerkin-based step by step linearizatio...

In this research, a functionally graded microbeam bonded with piezoelectric layers is analyzed under electric force. Static and dynamic instability due to the electric actuation is studied because of its importance in micro electro mechanical systems, especially in micro switches. In order to prevent pull-in instability, two piezoelectric layers are used as sensor and actuator. A current amplif...

This paper presents mechanical behavior of a functionally graded (FG) cantilever micro-beam subjected to a nonlinear electrostatic pressure and thermal moment considering effects of material length scale parameters. Material properties through the beam thickness direction are graded. The top surface of the micro-beam is made of pure metal and the bottom surface from a mixture of metal and ceram...

In this paper, a fracto-metallographic analysis was performed on the cracked specimens of cold drawn pearlitic steel subjected to fatigue tests. Fatigue cracks are transcollonial and exhibit a preference for fracturing pearlitic lamellae, with non-uniform crack opening displacement values, micro-discontinuities, branchings, bifurcations and frequent local deflections that create microstructural...