Advanced Materials Research Vols. 915-916

Abstract: Based on modal decomposition, an explicit formula for edge resonance solution in circular cylinders is presented here. Using the bi-orthogonality relation and singular value decomposition, the method could get the exact edge resonance frequency of circular cylinders. The calculation results are compared with numerical simulation results for verification.

Abstract: Experimental method and parameters to investigate the dynamic performances of an automatic tensioner are discussed. Parameters to evaluate the dynamic performances of a tensioner include dynamic stiffness, loss angle and equivalent viscous coefficient. Dynamic stiffness and loss angle can be measured directly, and the equivalent viscous coefficient can be calculated by torque-angular displacement loop which identified with the parameters including dynamic stiffness, loss angle, pre-load torque, pre-load angular displacement, excitation amplitude and excitation frequency. In this paper, the influences of excitation amplitude, excitation frequency and pre-load torque on the dynamic characteristics of tensioner are measured and investigated.

Abstract: The impact of certain extreme events on the construction index is of greatly importance which could be viewed as a huge turning to the index. In the paper, the Wenchuan Earthquake of China would be chosen as the extreme event and an EMD-based (Empirical Mode Decomposition) analysis approach would be used to test the earthquake’s impact. In the proposed method, a t-test is necessary to prove the significant level which could say the earthquake did have huge influence on the change of the construction index (399235.SZ) measured in Shenzhen stock market. Then the time series would be decomposed into six different modes and one residue which represent different turnings with different fluctuations and an average trend. Different fluctuations are caused by different factors but there is only one or several dominant modes can reflect the impact caused by certain extreme event which is the Wenchuan Earthquake of China in this study. Through a step-by-step analysis based on the EMD-based analysis approach, a simple solution would be obtained to estimate the huge impact caused by the Wenchuan Earthquake on the construction index which we name an EMD-based event analysis method.

Abstract: In the process of calculating the crankshaft frequency and vibration mode, free mode is always applied for the crankshaft modal analysis. Considering the effect of centrifugal force generated by the rotation to the crankshaft frequency and vibration mode, the frequency and vibration mode of multi-speed cases are calculated, and compared, which fully shows the vibration situation of the crankshaft in the process of actual working situations, the results match actual situation.

Abstract: Taking the deep foundation pit engineering of a Subway Station as background. The paper introduces the projects surroundings,geological and hydrological conditions of the proposed field and the retaining structural type. According to the engineering characteristics,the project was divided into four typical operating conditions,the deformation rules of deep foundation pit at subway station in tunneling are studied with the method of FLAC3D numerical simulation,the supporting structures choose by the bored piles and interior support. The analysis of the horizontal deformation of the retaining structures, the settlement law and the influence sphere of surrounding soil. The conclusion in this paper can provides reference for the reasonable design and safety construction of deep foundation pit.

Abstract: In the paper was examined the impact of biconnectivity of oscillations of single-mass system on the dynamic factor under unsteady dynamic impact.

Abstract: Finite element method is widely used in every field, in which ABAQUS is a typical product. For engineers and researchers, SHAKE91 is a good choice for seismic safety evaluation. For developing seismic response analysis for complicated cases, finite element method approach should be explored. An elastic layered model is built, which is calculated in SHAKE91 and ABAQUS respectively. The results of the two programs fitted well, which implies the correctness of the ABAQUS model. In the elastic model, simple boundary condition works well. In the future, more complex boundaries and dynamic constitutive models should be studied.

Abstract: Coupled vibration between transmission shaft and drive axle gears is one of the main factors influencing NVH in the FR transmission system. Based on the transmission shaft and drive axle gears, using UG to establish three-dimensional model, establishing flexible-body dynamics model and solving coupling vibration laws of transmission shaft and drive axle gears by ADAMS, and analyzing influencing factors on coupled vibration between transmission shaft and drive axle gears.It is of theoretic significance, for design parameters and installation matching between transmission shaft and drive axle gears.

Abstract: When more than one loads act on a structure,the combination of stochastic loads is generally considered in the design of the structure,Based on the theoretical derivation and numerical calculation analysis to the process of two common loads in Poisson square wave and Poisson impulse this paper presents the combination method of loads.i.e. The maximum intensity function of load combination is expressed by the cumulative distribution function in the limit state design. In addition,the result calculated during the limit state design is compared with those calculated by Turkstra and Monte Carlo methods and the analytical results show that the method proposed in this paper is feasible in the calculation of load combination.

Abstract: Based on the method for calculating seismic active earth pressure of soil-nailing retaining structures literature [ , the effect of horizontal seismic coefficient on seismic active earth pressure and the most dangerous sliding are analyzed in connection with practical engineering projects, and compared with the result which is not considered the seismic action. Results show that The existence of soil nails can effectively reduce the lateral pressure of supporting structures under earthquake ground motions and make the sliding surface slowly move to the wall back; Increased along with the height of soil nailing wall;With the increase of the height of soil nailing wall ,facing wall the sliding movement amplitude increase under the action of earthquake, and the soil nail length is growing.