Applied Mechanics and Materials Vols. 602-605

Abstract: Kinetic characteristics of chain drive system were investigated in this paper and some corresponding mathematical models were established. In accordance with the theory of chain drive, based on the multi-body dynamics software platform, a dynamic analysis model of timing bushing chain system for diesel engine was established. Chain tension force, chain contact force and chain fluctuation in a rotation cycle at different running speeds were analyzed. By analysis and evaluation these results, the kinematic and dynamic characteristics of the chain drive system during the operation could be effectively recognized, this research results can provide a basis for production tests.

Abstract: The finite element analysis software Solidworks Simulation is used to the modal analysis of the dynamic disc of the new-type plate-rolling crusher, its natural frequency and main vibration modes of preceding five orders are obtained. The analysis results show that while the natural frequency of preceding two orders of the dynamic disc is closed to the engagement frequency of the gears of the reducer casing, resonance occurs. So corresponding measures of avoiding resonance are proposed, the study offers theoretical references for the dynamic design of the dynamic disc.

Abstract: HyperMesh was used to mesh the absorber spring plate, and MATLAB was used to read-in grid node coordinate file and to carry on multi-target structure topological optimization design through the self-compiled program. Objective functions include rigidity, volume and fatigue life etc. model reconstitution, CAE analysis and experimental verification were completed according to the optimization result. Results showed that optimized spring plate met the using need and lightweight design was accomplished.

Abstract: To design a new product for fire extinguishing equipment, knowledge about customer requirements for selecting suitable characteristics is required. And Quality Function Deployment (QFD) is proposed as an effective design method to addresses the translation of customer requirements into product functional characteristics. So this paper describes an extension of QFD method aimed at representing customer needs, technological requirements, environmental impacts and their relationships with the product functionality during the conceptual design phase. At last this method could help designers to design a new conceptual product for fire extinguishing equipment.

Abstract: Driving comfort is one of the most important indexes for automobile comfort evaluation. The joint torque calculation model of the lower limb in driving posture is established in the presented work firstly. The relationship between cab layout parameters and the joint torque can be obtained through dynamical simulation in the MATLAB by employing Kane method. A new method based on muscular forces is proposed to evaluate the automobile comfortableness. The force of each muscle can be obtained by employing static optimization algorithm of inverse dynamics. The impact of cab layout parameters , joint torque and the muscular forces on driving comfort and the relationship between them can be found through the analysis. As an reference, these parameters can be used to optimize the cab and offer an important support for its optimization.

Abstract: The samples are prepared by vacuum sintering technology, and the effects of VC/NbC combined addition on the mechanical properties of the WC-8% Co alloys with superfine grain are investigated. The results show that: with the transformation of Co-doped inhibitors content, the grain growth is inhibited and the grain size 460nm at 0.4%NbC/0.4%VC. The mechanism that Co-doped NbC/VC on the effective reduction of ultrafine WC-8%Co cemented carbides was analyzed. The 0.4%NbC/0.4%VC addition equipped with the best integrated properties was obtained in this study. And sintered sample were investigated with SEM.

Abstract: In this paper, Sichuan Bonny provided excavator experimental as a platform ,to testing the efficiency of various energy-saving hydraulic circuit. Based on the original hydraulic system design and adding new energy recovery system, observing the energy saving effect. Summarizes the large excavator hydraulic system common energy problems, deal with the problems from different aspects of hydraulic energy-saving technology describes the present state of hydraulic energy-saving technologies , and described the development trend of hydraulic energy.So that allows people to comprehensive understanding of this technology, to promote this technology popularization and application.

Abstract: Studied the main theory about helical cylindrical spring design, based on the existing theory,found the parameters that affect helical spring's stiffness, size, stroke, and also how much they effect the parameters. Draw the curve which can be a reference for helical cylindrical spring design, put forward a method of cylindrical helical spring design, which is according to the installation dimensions and working stroke and applicable to the design of cylindrical helical spring when is given workspace and stroke. Provided a new reference for the design of cylindrical helical spring, with important significance to engineering design.

Abstract: A numerical approach is carried out to investigate the dynamic behavior of the CFRP strengthened pressure pipes subjected to impact load. In the FE analyses, Johnson-cook model is used to simulate metal subjected to large plastic strains and high strain rates, the fluid and pipe interaction is modeled by the surface-based fluid cavity to include the coupling effect between the deformation of the pipe and the internal pressure. Besides, the Hashin damage model is used to predict the damage of CFRP. The objectives of the numerical simulations are to capture the measured forming and crash history of the CFRP strengthened pressure pipes and gain an insight into the dynamic behavior of CFRP strengthened pressure pipes subject to impact load. The effects of internal pressure and the thickness of the CFRP are investigated, providing a detailed understanding of parameter sensitivity.

Abstract: Tire under-pressure will increase vehicle’s rolling resistance, additional fuel consumption and possibility of tire wear, which will magnify the possibility of a flat tire when vehicle drives at a high speed. In addition, an under-pressure tire will cause a smaller wheel radius, which influences wheel speed calculation in Anti-lock Braking System (ABS) and reduces the control robustness. In this paper, an under pressure compensation algorithm for wheel radius based on ABS wheel speed is proposed, which can improve the accuracy of ABS control and indirectly give early warning of a single under-pressure tire as well. Finally it has been validated by vehicle experiments.