As a driving element,the spiral torsion spring can control the release velocity by the optimization design of spring parameters and be used for separation devices,which is conducive to unlocking synchronicity and low-...As a driving element,the spiral torsion spring can control the release velocity by the optimization design of spring parameters and be used for separation devices,which is conducive to unlocking synchronicity and low-shock of the separation. On the basis of analyzing the performance requirements of the spiral torsion spring in a spacecraft device,the optimization design model of the spiral torsion spring is given, which takes the spiral torsion spring's length,width and thickness as the optimization variables,and the minimum volume as the optimization objective. The model considers output torque,strength,the maximal resetting load,holding force,and low shock as constraint conditions. A case is given to analyze the proposed model. The analysis results show the optimization scheme decreases the volume of the spiral torsion spring and meets the performance requirements of the separation device.展开更多
Negative stiffness mechanisms have great application potential in different fields, such as vibration isolation, energy absorption and mesh antenna unfolding. Although numerous compliant mechanisms with negative stiff...Negative stiffness mechanisms have great application potential in different fields, such as vibration isolation, energy absorption and mesh antenna unfolding. Although numerous compliant mechanisms with negative stiffness features have been implemented in literature, the designing work remains in its infancy, and proposing an original design strategy may open a new avenue for the future inventions. In this study, inspired by a toy, we developed a novel type of compliant mechanism composed of thin strips, possessing negative stiffness property under torsion. The negative stiffness feature is achieved by large deformation of the strips rather than mechanical buckling. As a consequence, the obtained negative stiffness segment covers a significantly long range. Demonstrated with examples, it was shown that the proposed mechanisms could be combined with other compliant mechanisms to realize long-range unusual torque-angle relationships, which can be used in different applications.展开更多
We discuss the feasibility of operating a torsion balance in the presence-of fixed masses positioned so that a decrease in gravitational potential energy experienced by the balance as it rotates nearly cancels the pos...We discuss the feasibility of operating a torsion balance in the presence-of fixed masses positioned so that a decrease in gravitational potential energy experienced by the balance as it rotates nearly cancels the positive energy associated with its twisting support fiber.Under these conditions the net effective torsion constant may in principle be made arbitrarily small.We dicuss an example of reduction by a factor of 100.展开更多
In order to solve the problem of real-time soft tissue torsion simulation in virtual surgeries,a torsion model based on coil spring is proposed to actualize real-time interactions and applications in virtual surgeries...In order to solve the problem of real-time soft tissue torsion simulation in virtual surgeries,a torsion model based on coil spring is proposed to actualize real-time interactions and applications in virtual surgeries. The proposed model is composed of several connected coil springs in series. The sum of torsion deformation on every coil is equivalent to the soft tissue surface deformation. The calculation of the model is simple because the method for calculating the torsion deformation for each coil spring is the same. The virtual surgery simulation system is established on PHANTOM OMNI haptic device based on the Open GL 3 D graphic interface and VC + + software,and it is used to simulate the torsion deformation of virtual legs and arms. Experimental results show that the proposed model can effectively simulate the torsion deformation of soft tissue while being of real-time performance and simplicity,which can well meet requirements of virtual operation simulations.展开更多
基金Natural Science Foundation of Liaoning Province,China(No.2015020121)Research Fund for the Doctoral Program of Higher Education of China(No.20122125120013)the Fundamental Research Funds for the Central Universities,China(Nos.3132015087,3132014303)
文摘As a driving element,the spiral torsion spring can control the release velocity by the optimization design of spring parameters and be used for separation devices,which is conducive to unlocking synchronicity and low-shock of the separation. On the basis of analyzing the performance requirements of the spiral torsion spring in a spacecraft device,the optimization design model of the spiral torsion spring is given, which takes the spiral torsion spring's length,width and thickness as the optimization variables,and the minimum volume as the optimization objective. The model considers output torque,strength,the maximal resetting load,holding force,and low shock as constraint conditions. A case is given to analyze the proposed model. The analysis results show the optimization scheme decreases the volume of the spiral torsion spring and meets the performance requirements of the separation device.
基金supported by the National Natural Science Foundation of China(11872221 and 11302114)the Major State Basic Research Development Program(2012CB821203)
文摘Negative stiffness mechanisms have great application potential in different fields, such as vibration isolation, energy absorption and mesh antenna unfolding. Although numerous compliant mechanisms with negative stiffness features have been implemented in literature, the designing work remains in its infancy, and proposing an original design strategy may open a new avenue for the future inventions. In this study, inspired by a toy, we developed a novel type of compliant mechanism composed of thin strips, possessing negative stiffness property under torsion. The negative stiffness feature is achieved by large deformation of the strips rather than mechanical buckling. As a consequence, the obtained negative stiffness segment covers a significantly long range. Demonstrated with examples, it was shown that the proposed mechanisms could be combined with other compliant mechanisms to realize long-range unusual torque-angle relationships, which can be used in different applications.
文摘We discuss the feasibility of operating a torsion balance in the presence-of fixed masses positioned so that a decrease in gravitational potential energy experienced by the balance as it rotates nearly cancels the positive energy associated with its twisting support fiber.Under these conditions the net effective torsion constant may in principle be made arbitrarily small.We dicuss an example of reduction by a factor of 100.
基金Supported by the National Natural Science Foundation of China(No.61502240,61502096,61304205,61773219)the Natural Science Foundation of Jiangsu Province(No.BK20141002,BK20150634)
文摘In order to solve the problem of real-time soft tissue torsion simulation in virtual surgeries,a torsion model based on coil spring is proposed to actualize real-time interactions and applications in virtual surgeries. The proposed model is composed of several connected coil springs in series. The sum of torsion deformation on every coil is equivalent to the soft tissue surface deformation. The calculation of the model is simple because the method for calculating the torsion deformation for each coil spring is the same. The virtual surgery simulation system is established on PHANTOM OMNI haptic device based on the Open GL 3 D graphic interface and VC + + software,and it is used to simulate the torsion deformation of virtual legs and arms. Experimental results show that the proposed model can effectively simulate the torsion deformation of soft tissue while being of real-time performance and simplicity,which can well meet requirements of virtual operation simulations.
