Applied Mechanics and Materials Vols. 496-500

Abstract: Dynamic substructure method has been widely used in analyzing the torsional vibration characteristics of multi-shaft transmission. However, the existing literatures extract substructures of the multi-shaft transmission by treating its gears and shaft as several rotors, resulting in complex displacement coordination relationships and making it difficult to build dynamic model for the whole system. In this paper, a new method to extract substructures of the multi-shaft transmission is proposed when analyzing its torsional vibration characteristics using the dynamic substructure method. The proposed method avoids analyzing the displacement coordination relationships for the gear meshing, making it easier and more effective to establish the dynamic model for multi-shaft transmission.

Abstract: This paper proposes a new two-component sensor balance to measure the thrust and torque of the propeller. Its principles of measuring force were derived and the procedures of balance measuring system were also provided according to the virtual instruments. The sensor balance was calibrated through the ground static calibration bench to verify its accuracy. And a ground static thrust experiment on a one-meter sized propeller model was carried out. By comparison, the experimental results of adopting the designed sensor balance basically tally with those of wind tunnel experiment, which proves that this sensor balance can be used in propeller experiments.

Abstract: By analyzing the force of the Coal Mine Rescue Robots swing arm brackets, the maximum torques of the Coal Mine Rescue Robots swing arm brackets are calculated, the results are applied into finite element model, the maximum stress of brackets are much smaller than allowable stresses of the materials, so there is a large optimise space. Optimum design of Swing Arm Brackets are carried out by changing materials and dimensions. After simulating analysis, it can be seen that the lightweight design for out-bracket have better effect through cutting out materials rather than changing its materials. The results of this optimization may conserve materials and reduce energy consumption. And it has significant in successfully applying the robot into the coal mine underground after disasters and improving the using time of the batteries.

Abstract: The wheel-rail contact is a boundary condition highly nonlinear complex problem, which need to accurately track the wheel-rail movement and the interaction contact stress between wheel-rail before and after the occurrence of wheel-rail contact, nonlinear contact stress of wheel-rail is analyzed through the contrast of finite element analysis and the actual detection, the experimental and theoretical calculation results show the compliance of the finite element model of wheel-rail, at the same time also point out some differences of theoretical calculation and actual manufacturing, which establish the theoretical and experimental foundation for the advanced research movement friction etc..

Abstract: Hoisting machinery is an important part of the equipment manufacturing industry, and the general bridge crane is the most widely used hoisting machinery. The main girder of bridge crane is the main load-bearing structure. Further, fatigue failure of main girder usually occurs not on the material itself but in the welding joint. The article has carried out three groups of experiments, which are experiment on fatigue property under vertical force, experiment on fatigue property under the comprehensive function of vertical force and horizontal force and experiment on failure mode of main girder under the prefabricated crack, to further discuss the effect of welding procedure on main girder fatigue property. Finally the following three conclusions are obtained. Firstly, the crack occurs closely to the middle position of welding place of the lower board and the main web, with the trend of scaling up along the main web perpendicular to the welding place. Secondly, the crack occurs on the main web close to the upper board, with the two-way expansion trend. Thirdly, fatigue failure cracks do not occur in the welding joint except the prefabricated crack position close to the square steel rail after the cyclic loading of two million times on main girder, which indicates that the uniformity of welding quality has an importance influence on the fatigue reliability of the whole main girder.

Abstract: The equivalent linearization method to calculate the stiffness parameters of the elastic element and damping parameters of the vehicle suspension is presented in this paper. With the virtual work principle, the nonlinear characteristics of the suspension are analyzed. The stiffness and damping of the suspension element based on the vibration response of the vehicle ride comfort are calculated. The numerical computation results of a double wishbone suspension with torsion bar show the presented method is feasible and effective.

Abstract: In this paper, a novel compact and light weight mechanical centrifugal friction speed limiter is designed for the miniaturization of mechanical systems. Details of design concerns are described. On this basis, complete and accurate mechanical model is established. Dynamic and steady-state analyses are also carried out. Moreover, it is proved that the performance of speed limiting has nothing to do with the gravity of centrifugal part. Finally, the theoretical model is verified by Adams software simulation under working conditions.

Abstract: Considering the self-structure of lithium-ion battery and features of lithium-ion battery casing machine, the detailed design and analysis were carried on the components of lithium-ion battery casing machine. The motion simulation and finite element analysis were conducted by ADAMS and MARC software. The results show that the structure is practicable and the design is reasonable.

Abstract: The limitations of traditional methods of the optimization design of combination sleeve are pointed out in this paper. The features and steps of the optimization design by using ANSYS are introduced. The steps and features of applying ANSYS to optimize the combination sleeve are introduced detailed with an example, and the solution to the key problem is introduced. The method has a high value for application and promotion.

Abstract: Apply FLUENT software to establish the water lubricated rubber stern tube bearing CFD model,study temperature and pressure distribution of the bearings at different speeds of rotation. It plays an important role in improving the performance of ship water lubricated stern tube bearing and security, reliability of propulsion system. The simulation results show that increasing the shaft speed in a certain range can reduce water film temperature, the effect is obvious especially at slow entrance velocity of bearings. Both high and low pressure ranges in the middle of bearings are enlarged with the increase of speed.