the nonlinear static pushover analysis technique is mostly used in the performance-based design of structures and it is favored over nonlinear response history analysis. however, the pushover analysis with fema load distributions losses its accuracy in estimating seismic responses of long period structures when higher mode effects are important. some procedures have been offered to consider thi...

engineering ceramics due to high-strength-to-weight ratio, wear and corrosion resistance, and high strength temperatures, in the industries especially in aerospace, automobile, electronics and computers are used widely. in attention to the  increasingly usage process of these material, applying of conventional machining methods  for producing  machined into complex and desired shapes or making ...

in this study, the vibration of cracked plates is investigated using the differential quadrature method and experimental modal analysis. the crack, which is assumed to be open, is modeled by the extended rotational spring. with its finite length, the crack divides the plate into six segments. then, the differential quadrature is applied to the governing differential equations of motion and the ...

An approximate numerical mthod is presented for analysis and determination of modal characteristics in straight, pretwisted non-unifom helicopter blades. The analysis considers the coupled flapwise bending (out of plane), chordwise bending (in plane), and torsion vibration of both rotating and non-rotating blades. The proposed method is based on the integral expansion of Green functions (struct...

An approximate numerical mthod is presented for analysis and determination of modal characteristics in straight, pretwisted non-unifom helicopter blades. The analysis considers the coupled flapwise bending (out of plane), chordwise bending (in plane), and torsion vibration of both rotating and non-rotating blades. The proposed method is based on the integral expansion of Green functions (struct...

According to the great importance of safety in aerospace industries, identification of dynamic parameters of related equipment by experimental tests in operating conditions has been in focus. Due to the existence of noise sources in these conditions the probability of fault occurrence may increases. This study investigates the effects of noise in the process of modal parameters identification b...

Split-hom together structure is a new heavy load rack structure, and its reliability needs to be verified. Through analyzing multimodal hom-connection principle from the perspective of bionics and contact mechanics, the article puts forward three kinds of hom-connection methods and establishes the finite element model and mathematical model of the rack. Afterwards, the finite element model and ...

In recent years some multi-mode pushover procedures taking into account higher mode effects, have been proposed. The responses of considered modes are combined by the quadratic combination rules, while using the elastic modal combination rules in the inelastic phases is not valid. Here, an optimum weighted mode combination method for nonlinear static analysis is presented. Genetic algorithm is ...