Structural health monitoring (SHM) systems operate online and test different materials using ultrasonic guided waves and piezoelectric smart materials. These systems are permanently installed on the structures and display information on the monitor screen. The user informs the engineers of the existing damage after observing signal loss which appears after damage is caused. In this paper health monitoring is done for plate shaped structures made of ST-37 steel. After conducting the experimental tests, the stored signals by the multi-layer artificial neural network algorithm is processed and the damage caused in the plate is detected. By analyzing the graphs, it becomes clear that after causing damage the signal amplitude decreases. In the experimental test two piezoelectric discs are used on a steel plate which have been installed using a strong adhesive. Using a strong adhesive improves wave, propagation in the structure. Developing innovative testing methods for the SHM system has caused better control in structures after assembly. تفاصيل المقالة

This research develops thermo-elastic analysis of a functionally graded cylinder under thermo-mechanical loadings. Heat conduction equation in cylindrical coordinate system is solved. Thermal conductivity coefficient is graded along the radial direction. By considering a symmetric distribution of temperature, loading and boundary conditions, strain-displacement and stress-strain relations can be developed. Material properties such as modulus of elasticity are graded along the radial direction. For validation of the obtained results; a complete numerical analysis using finite element approach is presented. تفاصيل المقالة

Stress concentration factors have been examined in a functionally graded material (FGM) plate withcentral holes in different shapes in this essay. The material properties change along the thickness ofplate. ABAQUS software has been utilized for modeling of problem in which subroutine ofABAQUS sub-program was used for modeling of the targeted material. The considering shapes forhole in plate are circular and elliptical in which stress concentration factors have been studied indifferent modes in respective of ellipse diameters. Similarly, stress concentration factors have beenanalyzed in the plate for various coefficients of FGM function. The results show that changes inmaterial properties and the shape of hole in plate affect the stress concentration factor around thehole. An experiment was implemented to determine verification of results from Finite ElementMethod (EFM). تفاصيل المقالة