Applied Mechanics and Materials Vols. 427-429

Abstract: By analyzing the difference between the vibration excitation sources of rubber-tired Light Rail Transit (LRT) and those of traditional drum-rail transit, the upper and lower limits of spatial angular frequency determined by the bridge vibration wavelength range were discussed, and the track irregularity samples of train-bridge space-coupling system for rubber-tired LRT were simulated by the trigonometric series method. The results show that 1.6m~80m bridge wavelength range can meet the needs of the train-bridge spatial vibration analysis. And the simulated track irregularity samples referring to the sixth grade track irregularity Power-Spectral-Density (PSD) of U.S. railways can be used as the vibration excitation sources of the train-bridge spatial vibration analysis of rubber-tired LRT.

Abstract: Plate-cone reticulated shell is a new type of space structures with good mechanical behavior and technical economy. In this dissertation, plate-cone reticulated shell is equated to double-layer reticulated shell with two kinds of material members. The internal forces and the displacement of plate-cone reticulated shell can be calculated by space truss displacement method.

Abstract: Plate-cone reticulated shell is a new type of space structures with good mechanical behavior and technical economy. In this paper, local buckling and influence factors of composite plates in plate-cone reticulated shell are analyzed with theory of composite plate and shell through composite structure finite element method, and the mechanical characteristics of composite plate-cone reticulated shell are studied, some important conclusions were obtained, which can provide theoretical foundation for practical design of composite plate-cone reticulated shell and composite plates.

Abstract: The fire resistance rating of concrete members coated with different thickness of fire-resistant coating was analyzed by experiment in the fire. Studies showed that the impact of CFRP and steel on the temperature field of the specimens was same, the fireproof effect of thick-layer fire-resistant coating for steel structure was obvious, the thickness of the fire-resistant coating and the fire performance are not proportional. It was identified that the best value of the thickness of fire-resistant coating is 40mm, and it provided the basis for fire protection design of reinforced concrete members after reinforcement.

Abstract: The technology of steel box girder shield and PLC synchronous pushing are used in the foundationl underpinning during the Yuzhen palace integrally lifting of Wudang Mountain for the first time. The characteristic of steel box girder is light weight, large internal operating space, high strength, and low friction coefficient with soil. The foundation underpinning of building is done by the steel box girder with PLC synchronous pushing system. The building is located on the integrity of good rigid chassis. The paper provides design principle of key component, design of PLC synchronous pushing system and related calculation method, and provides a new technology for protection building.

Abstract: To improve the performance of the multi-obstacle manipulation task of the telerobot in the precise interactive teleoperation environment, this paper proposes a novel spatial-motion-constraints virtual fixtures (VFs) method with two 3D flexible VFs, the warning pipe and the safe pipe, as well as a potential-collision-detection method based on these two flexible VFs. The safe pipe constructs the safe workspace dynamically for the robot while the warning one can detect the deviation from the EE to the reference path by adjusting the radius. Experiments show that the control mode employing our method can assist the operator more precisely in teleoperative tasks along with the reduction in the operating tension.

Abstract: According to the issue of CVT torque converter internal flow field such as the complexity and not easy to calculate, the channel model of torque converter is established by UG, the grid of channel model is generated by GAMBIT, the internal flow field of torque converter is simulated based on FLUENT while the pressure and velocity distribution of flow field are calculated under three different conditions. The results show that analyzing the flow field of torque converter by FLUENT has certain guiding significance for the design and optimization of torque converter.

Abstract: when the rolling part works in high speed, its nature frequency changes a lot due to stress stiffening and spin softening. Using a single rotor and a rotor with axis as an example, the first eight natural frequencies were obtained respectively through ANSYS after establishing models. Comparisons of nature frequencies of considering stress stiffening only, spin softening only, both stress stiffening and spin softening in a series of speeds were made. It was found that relatively large error would exist unless the effects of stress stiffening and spin softening were considered on nature frequency in high speeds.

Abstract: In the rugged topography of sugarcane field, to make the cutting platform keeping a setted height off field surface is one of the technical problems which combined sugarcane harvester is confronted with. Through studying the sugarcane field condition and cutting platform following system of combined sugarcane harvester, designed a type of cutting platform following system based on electro-hydraulic proportional technique, and simulated it with AMESim software.