Applied Mechanics and Materials Vol. 197

Abstract: The construction geological condition is complex in the transition section from the inclined shaft to the main hole. There are two kinds of construction schemes. After the comparison of the advantages and disadvantages of the two different construction schemes, it has selected the construction scheme of the rectangular pilot tunnel vertical to the main hole. This paper solve the construction problem of the transition section from the inclined shaft to the main hole of large cross section tunnel of passenger dedicated line under complicated geological conditions. According to the previous research results, the method can be used to large-cross section tunnel. The scaffold design and auxiliary construction measures is detailed. Compared with the expected duration, it completed the transition construction ahead of time with the speed superior to the ones of other similar works, and forming a safe and efficient construction situation.

Abstract: The cylinder-flat gauge of 0.56 mm heel-toe difference (HTD) flat with 3 mm-long plane ground on setover was calculated by the method of geometry. The change curves of cylinder-flat gauge were given by using MATLAB software under three conditions of 0.56 mm HTD flat, 0.56 mm HTD flat with 3 mm-long plane ground on setover, and 0.49 mm HTD flat. It conclude that the average gauge under 0.49 mm HTD adopted is smaller than that under 0.56 mm HTD flat with 3 mm-long plane ground on setover, and 0.49 mm HTD is realized easily in processing.

Abstract: The dynamic response of Variable Sweep Wing Aircraft (VSWA) with the wing sweeping is presented. The center of gravity (cg) of the aircraft, location of each wing partition , and moment of inertia alter significantly due to the wing morphing, resulting in considerably change of the dynamics of the aircraft. The extended equations of motion (EOMs) suitable for morphing wing aircraft are derived. Compared with the traditional EOMs, there are 4 additional forces and moments exhibiting in the extended EOMs due to the wing morphing. The results show that the additional forces and moments can affect the flight control considerably.

Abstract: Mechanical stages are common but very important tools to all the fields in the modern world. However, with the increasing demand for high-precision stage capability, it is found that the frictional characteristics play a more vital role for the stage motion and are worth of a careful investigation. Therefore, the problem of dynamic behavior and parameter identification for the sliding friction in a normal mechanical stage system operated in long range is studied in this paper, especially for the near transition regime between the presliding and sliding friction behaviors. A dynamic model and its corresponding identification method are proposed such that all the system parameters can identified from the derived relationships in a systematical way. The results show that the proposed method indeed works effectively with the experimental data regardless the complex composition and unevenly distributed contact conditions of the actual stage system.

Abstract: In view of disadvantages of domestic dispenser in control system and operation platform, we propose to take touch screen as human machine platform and adopt SMC6480 independent motion controller to control 3-axis linkage peristalsis dispenser. We devise system construction of peristalsis dispenser from hardware and software. Meanwhile, human machine interface is designed by touch screen

Abstract: The main components of the opposed biconinal cone screw high-pressure seawater hydraulic pump is the rubber bush and metal cone screw, and the interaction of the bush and cone screw is one of the main factors affecting the novel pump performance. The deformation and stress of the bush and cone screw under the initial interference is analyzed by the nonlinear finite element analysis. The analysis shows that: under the effect of the initial interference, large displacement is present to the radial surface of the cone screw, and the displacement of the radial surface mainly affects the displacement vector sum of the cone screw, and the deformation decreases gradually from the middle to the ends of the cone screw, while the cone screw is bending; the deformation in three direction of the bush is close to each other, but the location of the maximum displacement in each direction is different; with the shrink range increasing, the deformation of the cone screw and bush increases, but the deformation of the cone screw is much smaller than that of bush, so the deformation of the bush mainly affects the seal between the cone screw and bush, and the shrink range between the cone screw and bush decreases because of the deformation of the bush. Over the role of the interference force, the maximum von mises stress of the cone screw is an order larger than that of bush, and the maximum von mises stress both increases with the shrink range increasing; although shrink range is different, the location of the maximum von mises about the cone screw and bush is the same.

Abstract: In the multibody dynamics analysis for motor vehicle, engine excitation, as a major excitation affecting the dynamic behavior of motorcycle frame, should be discussed. In this paper, a real-sized virtual engine model is established to replace lumped mass sphere ever discussed in dynamic simulation of vehicle, on which elaborate dynamic simulation of the valve train in engine is conducted at working condition to investigate the dynamic response of frame. The vertical acceleration response of the frame is achieved by using solution formulations set in professional program, and the comparison is discussed between different simulation results of frame dynamic behavior with or without engine excitation to determine the significance of dynamic simulation with considering the interaction between excitation and mechanism which is then utilized to discuss the vibration and smoothness performance of whole mechanical system.

Abstract: At present, limited work was reported on the exact solution of axial stress for a multilayered pressure vessel subjected to mechanical and thermal loads. However, the axial stress plays an important role to the structural strength due to the influence of thermal load. Based on the theory of thermo-elasticity and finite element (FE) technology, therefore, the exact solution and numerical solution were constructed for a multilayered urea synthesis tower made of different kinds of materials subjected to an internal pressure and a thermal load. Results show good agreement between the theoretical solution and numerical solution, and thus it demonstrates the reliability of the derivation process and developed calculation formula, which would be helpful for more precise calculation and scientific design of the multilayered pressure vessel.

Abstract: In this paper we give the conjugated system of the discrete system of the two-span beam with two free-ends, which is a discrete system of two-span continuous beam with two clamped-ends and an internal pin. The sign-oscillating property of the stiffness matrix of the conjugated system is proved. And the basic oscillating properties of the frequencies and “displacement” modes of the conjugated system are determined. Furthermore, some qualitative properties owned by displacement modes, rotation modes, moment modes and shearing force modes of the discrete system of the two-span beam with two free-ends are obtained.

Abstract: Stearyltrimethyl ammonium bromide(STAB) was used for organic modification of bentonite and then ball milled the modified bentonite. The organically modified bentonite was analyzed by FT-IR and XRD. The results show that the stearyltrimethyl ammonium bromide has been interalated into the layers of bentonite. The layer distance of the bentonite is increased from 1.256nm to 2.694nm. The appropriate experimental conditions of interplanar spacing increasing were the dosage of STAB 40%, reaction time 4h, temperature 75°C. The ball milled organically modified bentonite was analyzed by SEM. The results show that the particle mainly reach submicron to nanometer when ball mill 2h. The particle size distribution range is from 100nm to 500nm. Ball milled organically modified bentonite/ cationic guar gum(CGG) can improve retention rate of paper-process reconstituted tobacco pulp obviously than organically modified bentonite/CGG because of smaller grains and better unigormity of ball milled bentonite.