Applied Mechanics and Materials Vol. 387

Abstract: Precision ball planetary drive is mainly composed of non-backlash cycloid ball reduction speed mechanism and non-backlash ball ring groove equal speed output mechanism (NBRGEO mechanism or called W mechanism). The three-dimension contact force is analyzed. The nonlinear mechanics model of NBRGEO mechanism was established. The formulas of contact force and stress were deduced. A numerical example is intended to illustrate the presented method of contact force analysis by using of computer program. Therefore, the contact force and stress distributing characteristics of NBRGEO mechanism is acquired. The research results offer theoretical basis for the design of NBRGEO mechanism of the precision ball planetary drive and the research of other precision planetary transmission.

Abstract: The thrust rod is the key load-bearing part of the balanced suspension on heavy commercial vehicle. In order to optimize the structure and study the durability of it, we carried out the force and simulation analysis. In this paper, the model of thrust rod and guide mechanism was simplified. Under all driving conditions, force analysis was done for fully-loaded vehicle and force calculation formulae of thrust rods in different directions were derived. Multi-body dynamics model of the vehicle was established with ADAMS and we compared the differences of the two algorithms. Then the results of the two algorithms were compared with the load spectrum test results. We find the calculated results are in good agreement with engineering requirements.

Abstract: The main focus is to present the theoretical methods to analyze the slide destruction reinforced by grass, geogrid, and revetment in a rigid grid-pile composite foundation. The methods are based on the balance condition of the slope. Using these methods, the influence of the internal friction angle of the embankment fill on the reinforced thickness of grass, geogrid and revetment at different slope angles are investigated. The results show that the reinforced thickness of grass, geogrid and revetment decreases with increased the internal friction angle of the embankment fill. The increase in the slope angle contributes much to the increase in the reinforced thickness.

Abstract: This paper studies on the waste fiber strength test of 88 concrete beams crack , the beams section-dimension are 100mm×100mm and length 500mm. Research on recycled aggregate replacement ratio, the waste fiber length and incorporation, the crack height-ratio effect on fracture toughness of concrete. The result indicates that the waste fibers can effectively limit extension and perforation of crack of recycled aggregate, increasing the ductility of concrete, enhancing fracture properties of concrete and conducive to the improvement of fracture toughness of concrete.

Abstract: The parallel grooved multi-layer winding drum can wind rapidly and reliably compared to traditional multi-layer winding drum, because of the special groove which is generated by circular and helical motion. The present paper represented the key winding stage for parallel grooved drum was the helical motion in first circle on the second layer, and the stage was simulated in ADAMS under several factors as fleet angle, winding linear velocity and rope tension. Taguchi method was adopted to estimate the winding performance through two simulation outputs, including the time delay compared to ideal time and the sum of amplitude error during the delayed time. Experiment was applied by considering more factors than that in ADAMS, and the experiment results could verify the validity of simulation in ADAMS. The simulation and experiment results showed that the optimal winding performance could be obtained with certain combination of factors.

Abstract: Only the basic wall thickness of drum is taken under consideration in traditional parallel grooved drum strength analysis, which is quite conservative for ignoring the thickness of the groove. So in this paper, it is aimed at comparing the strength simulation results for two drum models with and without the thickness of the groove and analyzing the stress distribution of the drum structure, which provides reference for the structure design and optimization of the drum.

Abstract: The arch bridge with oblique arch rib and bending girder, as a special type of structural system,construction control of which is very complex, especially making scheme of tensioning suspenders in view of the spatial mechanical characteristics of girder and arch bearing bending moment and torsional moment inside and outside surface. Take the Tongtai Bridge with suspenders of spatial asymmetric layout as an engineering case, three kinds of tensioning schemes are put forward and carried out a detailed demonstration besed on comprehensively considering the effecting factors such as support reaction and bridge deck pavement. The results show that the recommended tensioning scheme ensures the structural safety in construction process,avoids the concrete bridge deck pavement cracking and bearing void and makes the bridge in better mechanical state,which provide a technical reference for similar bridge construction with complex structural system.

Abstract: A method for the vibration and noise reduction of a typical aircraft panel structure under noise excitations is studied. The noise excitations are caused by travelling wave test device, and the experimental is performed by the piezoelectric switching shunt circuit based on the piezoelectric effect.

Abstract: Crack statically growing would induce the re-distribution of the stress and strain at the crack tip for power hardening materials, and the process of crack statically growing would be affected by the change of the stress and strain at the crack tip. To understand the effect of crack statically growing on the stress and strain at the crack tip, a simulation and analysis of the stress and strain at the stable growing crack tip is performed by using elastic-plastic finite element software for the power hardening materials in this paper, which establishes a foundation for improving the capability of predicting environmentally assisted cracking growth rate in key structural materials of nuclear power plants.

Abstract: The Fenwei Basin can be the most developed area of ground fissures as well as the associated geo-hazard in China and even in the world .Considering the ground fissure disasters influence on site condition, especially on the dynamic characteristics and dynamic response of site soil, in this paper, under the condition of constant pressure consolidation, consolidated undrained dynamic triaxial tests are carried on Xi'an area ground fissures belt loess with different confining pressures and dynamical parameters are obtained. Based on the experimental results, the dynamic stress-strain relationship, the change laws of dynamic shear modulus and damping ratio are analyzed. The equivalent visco-elastic constitutive model is also established.