Using a nonlinear time varying tyre model, this paper simulatively analyzes the influence of road surface roughness amplitude and road spatial frequency on automobile ground adhesion ability. The result shows that wi...Using a nonlinear time varying tyre model, this paper simulatively analyzes the influence of road surface roughness amplitude and road spatial frequency on automobile ground adhesion ability. The result shows that with the increase of road surface roughness, the tyre adhesion ability declines, and the automotive braking distance increases. Moreover, the reliability of the nonlinear time varying tyre model in reflecting the influence of the road surface roughness is validated. It is testified that this model is an effective dynamic one in the simulation of automotive braking performance on uneven road.展开更多
The control method of rubber tyre gantry （RTG） spreader in Qingdao Port Container Terminal is logic board control,which has many shortcomings such as expensive spare parts and high faults.This paper designs a new co...The control method of rubber tyre gantry （RTG） spreader in Qingdao Port Container Terminal is logic board control,which has many shortcomings such as expensive spare parts and high faults.This paper designs a new control system using programmable logic controller （PLC） centralized control to replace the original logic board control.The new system mainly contains complete ELME spreader control scheme design,hardware selection and PLC control program development.Its field application shows that the system has characteristics of high efficiency,low running cost,easy maintenance.展开更多
The most conventional vehicle pretensioner system consists of an internal gear pair with involute teeth. However, it has been well known that the corresponding gear pairs are relatively weak under the situation of imp...The most conventional vehicle pretensioner system consists of an internal gear pair with involute teeth. However, it has been well known that the corresponding gear pairs are relatively weak under the situation of impact loadings. To improve this phenomenon, a new pretensioning gear system with cycloid teeth rather than the involute ones was proposed, and dual cycloidal gear mechanisms were designed for satisfying geometric constraints and dynamic loading conditions. The simulations of the prototypes were conducted by LS-DYNA program and the experiments for a prototype were performed for a dynamic model with impact loading devices. The results show that the better operation and the smoother motion are confirmed in the proposed cycloidal gear system rather than the conventional one without interferences between gear teeth under the impact of a crash.展开更多
In order to obtain satisfactory mechanical properties for the cam used in high-power ship diesel engines, a new quenching technology was proposed by designing a two-stage quenching process with an alkaline bath as the...In order to obtain satisfactory mechanical properties for the cam used in high-power ship diesel engines, a new quenching technology was proposed by designing a two-stage quenching process with an alkaline bath as the quenching medium. To demonstrate the effectiveness of the proposed new quenching technology, both numerical analysis and experimental study were performed. The new quenching technology was analyzed using finite element method. The combined effects of the temperature, stress and microstructure fields were investigated considering nonlinear material properties. Finally, an experimental study was performed to verify the effectiveness of the proposed new quenching technology. The numerical results show that internal stress is affected by both thermal stress and transformation stress. In addition, the direction of the internal stress is changed several times due to thermal interaction and microstructure evolution during the quenching process. The experimental results show that the proposed new quenching technology significantly improves the mechanical properties and microstructures of the cam. The tensile strength, the impact resistance and the hardness value of the cam by the proposed new quenching technology are improved by 4.3%, 8.9% and 3.5% compared with those by the traditional quenching technology. Moreover, the residual stress and cam shape deformation are reduced by 40.0% and 48.9% respectively for the cam manufactured by the new quenching technology.展开更多
The determination of digging resistance is of decisive importance when evaluating the mining process of digging-wheel excavators. Methodic of measuring and determinant relations （formulae） are different in various c...The determination of digging resistance is of decisive importance when evaluating the mining process of digging-wheel excavators. Methodic of measuring and determinant relations （formulae） are different in various countries and by the comparison of them, underlying data for complex and objective evaluation using the knowledge from the field of rock disintegration can be obtained. In virtue of analysis of many measurements in situ, rather high specific power consumption with a wheel of excavator has been proved. What was the criterion for evaluation was the power consumption related to the volume of a rock disintegrated per unit time. From theoretical analyses, possibilities of eliminating a negative influence of the human factor upon the mining process and thus possibilities of optimum utilizing the power input of a wheel drive follow.展开更多
To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a math...To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.展开更多
文摘Using a nonlinear time varying tyre model, this paper simulatively analyzes the influence of road surface roughness amplitude and road spatial frequency on automobile ground adhesion ability. The result shows that with the increase of road surface roughness, the tyre adhesion ability declines, and the automotive braking distance increases. Moreover, the reliability of the nonlinear time varying tyre model in reflecting the influence of the road surface roughness is validated. It is testified that this model is an effective dynamic one in the simulation of automotive braking performance on uneven road.
基金Shandong University of Science and Technology Spring Buds Program(No.2010AZZ170)
文摘The control method of rubber tyre gantry （RTG） spreader in Qingdao Port Container Terminal is logic board control,which has many shortcomings such as expensive spare parts and high faults.This paper designs a new control system using programmable logic controller （PLC） centralized control to replace the original logic board control.The new system mainly contains complete ELME spreader control scheme design,hardware selection and PLC control program development.Its field application shows that the system has characteristics of high efficiency,low running cost,easy maintenance.
基金supported by the Changwon National University in 2011-2012,Korea
文摘The most conventional vehicle pretensioner system consists of an internal gear pair with involute teeth. However, it has been well known that the corresponding gear pairs are relatively weak under the situation of impact loadings. To improve this phenomenon, a new pretensioning gear system with cycloid teeth rather than the involute ones was proposed, and dual cycloidal gear mechanisms were designed for satisfying geometric constraints and dynamic loading conditions. The simulations of the prototypes were conducted by LS-DYNA program and the experiments for a prototype were performed for a dynamic model with impact loading devices. The results show that the better operation and the smoother motion are confirmed in the proposed cycloidal gear system rather than the conventional one without interferences between gear teeth under the impact of a crash.
基金Project(50875268) supported by the National Natural Science Foundation of China Project(CSTC2008AB3057) supported by Foundation of Chongqing Science and Technology Commission, China+1 种基金 Project(108107) supported by the Key Project of Ministry of Education of China Project(50925518) supported by the National Science Fund for Distinguished Young Scholars
文摘In order to obtain satisfactory mechanical properties for the cam used in high-power ship diesel engines, a new quenching technology was proposed by designing a two-stage quenching process with an alkaline bath as the quenching medium. To demonstrate the effectiveness of the proposed new quenching technology, both numerical analysis and experimental study were performed. The new quenching technology was analyzed using finite element method. The combined effects of the temperature, stress and microstructure fields were investigated considering nonlinear material properties. Finally, an experimental study was performed to verify the effectiveness of the proposed new quenching technology. The numerical results show that internal stress is affected by both thermal stress and transformation stress. In addition, the direction of the internal stress is changed several times due to thermal interaction and microstructure evolution during the quenching process. The experimental results show that the proposed new quenching technology significantly improves the mechanical properties and microstructures of the cam. The tensile strength, the impact resistance and the hardness value of the cam by the proposed new quenching technology are improved by 4.3%, 8.9% and 3.5% compared with those by the traditional quenching technology. Moreover, the residual stress and cam shape deformation are reduced by 40.0% and 48.9% respectively for the cam manufactured by the new quenching technology.
文摘The determination of digging resistance is of decisive importance when evaluating the mining process of digging-wheel excavators. Methodic of measuring and determinant relations （formulae） are different in various countries and by the comparison of them, underlying data for complex and objective evaluation using the knowledge from the field of rock disintegration can be obtained. In virtue of analysis of many measurements in situ, rather high specific power consumption with a wheel of excavator has been proved. What was the criterion for evaluation was the power consumption related to the volume of a rock disintegrated per unit time. From theoretical analyses, possibilities of eliminating a negative influence of the human factor upon the mining process and thus possibilities of optimum utilizing the power input of a wheel drive follow.
文摘To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.
