Applied Mechanics and Materials Vol. 189

Abstract: Broken rules of cylindrical steel shell subjected to internal blast loads is the foundation for conducting safety assessment and failure analysis of explosion containment vessels. The experiments were carried out broken rules of the cylindrical steel shells subjected to internal blast loadings at the centers. The elastic-plastic response of cylindrical steel shells was conducted using nonlinear dynamic finite element analysis code LS-DYNA. The results show that the deformation was’t a discrepancy in the explosion center of the cylindrical steel shell in same space, and the deformation descended slower along with thickness augmentation in the end of explosion center. The radial stress、hoop stress and axial stress was a discrepancy in the thickness way of cylindrical steel shell of explosion center The most leading cause of destructivity of cylindrical steel shell was that inner wall bearing normal stress and exterior wall bearing tensile stress; the hoop stress was broken more than axial stress cylindrical steel shell. The whole process was presenting hoop fractured and axial growth.

Abstract: Dynamic fracture of explosion containment vessels subjected to internal blast loads is the foundation for conducting safety assessment and failure analysis of explosion containment vessels. The experiments were carried out to investigate dynamic fracture characteristics of cylindrical steel shells subjected to internal blast loadings at the centers. The elastic-plastic response of cylindrical steel shells was conducted using nonlinear dynamic finite element analysis code LS-DYNA. The fracture mode and fracture mechanism of a cylindrical shell were specially studied through analysis of deformation， macrographs of fracture surface and elastic-plastic response. The results show that dynamical ductility deformations appear and the shear bands form when the cylindrical steel shell expands under internal blast loading. The cylindrical steel shell fractures preferentially along the shear bands due to its softening effect. The fracture mechanism is that the shear bands tear under tensile circumferential stress. The shear bands and the tensile circumferential stress dominate the final fracture mode. The fracture mode is of the ductile fracture.

Abstract: To research the problem of part’s dimensional accuracy error easily occurred in hot press forming, a B-Pillar on one domestic car was set as example, the dimensional of the actual part and its model diagram were compared by means of ATOS optical scanner. By recording the the process parameters used in practical production, the effect trend of three key process parameters on part’s dimensional accuracy was summarized, process parameters suitable for practical production were gained.

Abstract: Based on the magnetic theory, the paper reviewed the factors of affecting the distribution of magnetic flux leakage (MFL) on the ferromagnetic material and analyzed the wire rope defects characters from MFL signal. A non-destructive testing (NDT) instrument of steel wire rope using magnetic flux leakage was presented in this paper. By using permanent magnets to magnetize wire rope and using Hall element arrays to test MFL, Intelligent signal processing was applied for effective discrimination of wire rope’s flaws. The experiment results show the degree and the width of defects, the annular distribution of localized flaws such as concentrated or dispersive broken wires can be well distinguished. The instrument can be used conveniently with good resolution and repeatability and can meet the requirement of real time.

Abstract: This paper mainly introduced one kind of new E-shape Steel Damper structure performance. The finite element method was applied in the E-shape Steel Damper structure performance evaluation. The damper model was set up and stress analysis was executed to predict the stress distribution under the working load in Abaqus. Besides, the real test in lab was accomplished to determine the site where the destruction took place and the reason why it happened. The test result verified that the simulation was correct and reliable. Study on the E-shape Steel Damper performance based on above both methods revealed that excessive plastic deformation was the main factor to cause the damper destruction to occur.

Abstract: Because of the need of rapid detection of internal defects and embedded object in concrete structures, a detecting method with linear array probes is presented here, which is the high-resolution and efficient imaging technique for concrete structures by combining with synthetic aperture focusing technique (SAFT). Firstly, array simulation data are processed to be amalgamated B-scan data of concrete structures according to the structural characteristics of linear array; And then the B-scan data are reconstructed in the light of geometrical relation of ultrasonic path and SAFT; At last, the structural imaging figure are calculated. It can be shown from simulation results that the method is effective, and the embedded object in model can be identified effectively.

Abstract: Through the cracks because of influence of external temperature, and mixed thermal stress in the approximate calculation of the proposed measures to prevent the multi-storey top floor vertical wall cracks, to be prevented in the design, engineering examples by design better buildings products.

Abstract: A ring-shaped low-frequency resonator operating in the in-plane (2,1) mode was designed and fabricated utilizing anodic bonding of a 9-µm-thick single-crystal silicon to a glass substrate. Although the gap between the ring and the driving electrode was relatively large (900 nm), a high quality factor of 4212 at 1.609 MHz was realized. The motional resistance was 1.853 MW. In addition, the resonant frequency was electrically tuned by varying the dc bias of drive electrodes with 21.5 ppm/V. Therefore, it was expected that this resonator could possibly replace low frequency quarts resonators of a few MHz ranges.

Abstract: Analysis of vehicle ride comfort mainly refers to the vibration and shock environment impact on occupant comfort within certain limits, which will not make people feel comfortable, fatigue and even damage to health performance. Therefore, ride comfort is evaluated mainly based on subjective feelings of the crew, but also for the truck to maintain the performance of the goods in good condition; it is the main performance of modern high-speed car vehicle. The paper proposed a simulation modeling of the vehicle in ADAMS based on the multi-body dynamics theory; we made analysis of vehicle ride comfort on a random road. The result presents the process of building vehicle model and analysis of ride comfort and provides a basis for optimization of vehicle parameters. With this optimized design, the vibration of the vehicle has very significant performance improvements.

Abstract: In order to improve the signal-noise rate (SNR) of the acceleration sensor system, this article analysis of the design principles of a novel surface acoustic wave (SAW) acceleration sensor with cantilever beam using ST-X quartz. The main structure of the novel SAW acceleration sensor is composed of two oscillator, a mixer and a low pass filter to get the difference frequency structure, which can inhibit temperature drift and lateral acceleration impact. The two oscillator have the same structure, which is constitute of a low insertion loss SAW delay line and a feedback amplifier. This article shows the simulation results of the force analysis of the cantilever beam free end using ANSYS finite element analysis software. The novel acceleration sensor has potential applications in portable mobile devices or automotive airbags fields.