Papers by Author: Wen Zhong Qu

Abstract: In this paper, a FEA model of non-normal(considering yaw angle and oblique angle) penetration into reinforced concrete is established by using software ANSYS/LS-DYNA. In order to validate the digital model which is sensitive to material parameters,mesh size,ect. Amounts of numerical simulations are performed. The numerical results of a process of peneration are compared with the experimental results, and a good agreement is obtained.In the study,the residual velocity and the ballistic attitude when a projectile penetrates into a reinforced concrete target are focused on, the relationship between positive yaw angle and negative yaw angle with the penetration capacity of the projectile is investigated. The results obtained by the numerical approach are useful for predicting the response of the penetration, and the proposed numerical simulation methods may be very beneficial to some experiment of perforation of reinforced concrete structures.

Abstract: The hysteresis dynamic behavior of metal rubber mathematically modeled with a practical method is studied, and the method of parameter separated identification is presented with details. Parameters of the model are identified with the test data of metal rubber, from which the theoretical loops are reconstructed, and the mechanism of the nonlinear damping behavior of the metal rubber is investigated. The theoretical loops and the experimental one are close to each other with satisfactory accuracy. The result shows that with the simple mathematical form and the satisfactory precision, the mixed damping model can be used effectively in practical engineering. This study provides a practical and effective method in modeling and the parameter identification of the metal rubber isolator.

Abstract: Structure vibration test plays an important role in dynamic design, but in most cases the experimental data we get is always limited and insufficient for succeeding upgrade and optimization. The response prediction technique presented in this paper is the corresponding technique to deduce the full field response from the limited data obtained by simple vibration test instead of conducting the full-size test. SEREP (System Equivalent Reduction-Expansion Process) method was used to conduct the prediction research and the procedure was elaborated in detail theoretically first, then several simulations were carried on to demonstrate the prediction procedure, inspect the accuracy under various loads and investigate the factors which may influence the accuracy including the number of modes used in the prediction, the noise, and the measured points. Results show that this method has excellent accuracy and good adaptability to various loads as long as a sufficient set of orthogonal mode shapes participate in the prediction procedure.

Abstract: Structural health monitoring (SHM) is an emerging research area with multiple applications. Lamb waves are ultrasonic elastic waves that travel inside and along thin plates and is frequently used as diagnostic tools to detect damage in plate-like structures. In this paper, a transient dynamic finite element simulation of Lamb wave with piezoelectric transducers for damage detection in a composite plate is carried out. The embedded cross-shaped piezoelectric active sensor arrays were used to generate and receive guided Lamb waves propagating in the plate structure. A full-scale FEM model for the laminate was created using three-dimensional eight-node layered structural solid element and piezoelectric active sensors were created using coupled field elements on the commercial finite element code ANSYS platform. The beam forming technique of Lamb waves is used to locate damage in the plate .The results of the numerical simulation demonstrate the effectiveness of the approach.