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
A novel long period passive vertical vibration isolatorconstructed by mounting reverse pendu- lums on two pairs of torsionsprings is presented. By theoretical analysis and numericalcalculation, it is shown that the is...A novel long period passive vertical vibration isolatorconstructed by mounting reverse pendu- lums on two pairs of torsionsprings is presented. By theoretical analysis and numericalcalculation, it is shown that the isolator can achieve much longerresonant period due to gravitational positive feedback and is smallerin size than the current torsion spring isolators with the samegeometric parameters.展开更多
For solar array deployment,most existing studies mainly focus on modeling method of deployment dynamics,characteristics of hinges,and synchronization mechanisms.However,torsion springs,which work as the drive mechanis...For solar array deployment,most existing studies mainly focus on modeling method of deployment dynamics,characteristics of hinges,and synchronization mechanisms.However,torsion springs,which work as the drive mechanisms,have hardly attracted people's attention.In this study,the influence of the parameters of torsion springs on the deployment behavior of a solar array system with clearance joint is investigated by simulation experiments.The experimental results indicate that the deployment performances are very sensitive to the parameter values of the torsion spring.Suitable torsion springs are highly needed to improve the deployment dynamics of solar array system.Therefore,a multi-objective optimization method for the design of torsion springs is proposed.The objective of the optimization is to make the contact-impact force in revolute joint and the mass of the torsion spring minimum under the constraints of deployment time and structure strength.Finally,the effectiveness of the multi-objective optimization method is verified by an optimization example of solar array system.展开更多
This study represents the influence on exhaust performance by active muffler valve spring.The main experimental parameters were engine speeds and torsion coil spring constants in the active muffler.When the muffler va...This study represents the influence on exhaust performance by active muffler valve spring.The main experimental parameters were engine speeds and torsion coil spring constants in the active muffler.When the muffler valve spring has a low spring constant of k=0.75,the sound pressure level was low at the region of engine speed 2000 to 2500 r/min,and the velocity of exhaust gas was high at spring constant k=0.75.When the engine speed was under 1500 r/min,the mean concentration of CO was high in case without muffler valve.When the engine speed in the range of 1600 to 2600 r/min with spring constant k=0.75,the mean HC concentration showed the lowest value.Without muffler valve,the temperature in the muffler was higher than the case with muffler valve.This research represented that the performance of the active muffler valve spring constant k=0.75 was higher than that without muffler valve and valve spring constant k=0.70.Among the three cases of experimental condition,with a spring constant k=0.75,0.70 and without muffler valve,the exhaust performance was high in case active muffler valve spring constant k=0.70.展开更多
Vibration reduction has always been one of hot and important topics in mechanical engineering,especially for the special measurement instrument.In this paper,a novel limb-inspired bionic structure is proposed to gener...Vibration reduction has always been one of hot and important topics in mechanical engineering,especially for the special measurement instrument.In this paper,a novel limb-inspired bionic structure is proposed to generate negative stiffness and design a new quasi-zero stiffness isolator via torsion springs,distinguishing from the existing tension spring structures in the literature.The nonlinear mathematical model of the proposed structure is developed and the corresponding dynamic properties are further investigated by using the Harmonic Balance method and ADAMS verification.To evaluate the vibration isolation performance,typical three-springs quasi-zero stiffness(TS QZS)system is selected to compare with the proposed bionic structure.And the graphical processing unit(GPU)parallel technology is applied to perform necessary two-parameter analyses,providing more insights into the effects of parameters on the transmissibility.It is shown that the proposed structure can show advantages over the typical TS QZS system in a wider vibration isolation range for harmonic excitation case and shorter decay time for the impact excitation case.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the Post-doctoral Foundation of Huazhong University of Science and Technology
文摘A novel long period passive vertical vibration isolatorconstructed by mounting reverse pendu- lums on two pairs of torsionsprings is presented. By theoretical analysis and numericalcalculation, it is shown that the isolator can achieve much longerresonant period due to gravitational positive feedback and is smallerin size than the current torsion spring isolators with the samegeometric parameters.
基金the Project of Ministry of Education and Ministry of Finance of China(No.201335)
文摘For solar array deployment,most existing studies mainly focus on modeling method of deployment dynamics,characteristics of hinges,and synchronization mechanisms.However,torsion springs,which work as the drive mechanisms,have hardly attracted people's attention.In this study,the influence of the parameters of torsion springs on the deployment behavior of a solar array system with clearance joint is investigated by simulation experiments.The experimental results indicate that the deployment performances are very sensitive to the parameter values of the torsion spring.Suitable torsion springs are highly needed to improve the deployment dynamics of solar array system.Therefore,a multi-objective optimization method for the design of torsion springs is proposed.The objective of the optimization is to make the contact-impact force in revolute joint and the mass of the torsion spring minimum under the constraints of deployment time and structure strength.Finally,the effectiveness of the multi-objective optimization method is verified by an optimization example of solar array system.
基金This work was supported by the Brain Korea 21 Projects,and the authors gratefully appreciate the support.
文摘This study represents the influence on exhaust performance by active muffler valve spring.The main experimental parameters were engine speeds and torsion coil spring constants in the active muffler.When the muffler valve spring has a low spring constant of k=0.75,the sound pressure level was low at the region of engine speed 2000 to 2500 r/min,and the velocity of exhaust gas was high at spring constant k=0.75.When the engine speed was under 1500 r/min,the mean concentration of CO was high in case without muffler valve.When the engine speed in the range of 1600 to 2600 r/min with spring constant k=0.75,the mean HC concentration showed the lowest value.Without muffler valve,the temperature in the muffler was higher than the case with muffler valve.This research represented that the performance of the active muffler valve spring constant k=0.75 was higher than that without muffler valve and valve spring constant k=0.70.Among the three cases of experimental condition,with a spring constant k=0.75,0.70 and without muffler valve,the exhaust performance was high in case active muffler valve spring constant k=0.70.
基金supported by the National Natural Science Foundation of China(Grants 11832009 and 11672104)the Chair Professor of Lotus Scholars Program in Hunan province(Grants XJT2015408)。
文摘Vibration reduction has always been one of hot and important topics in mechanical engineering,especially for the special measurement instrument.In this paper,a novel limb-inspired bionic structure is proposed to generate negative stiffness and design a new quasi-zero stiffness isolator via torsion springs,distinguishing from the existing tension spring structures in the literature.The nonlinear mathematical model of the proposed structure is developed and the corresponding dynamic properties are further investigated by using the Harmonic Balance method and ADAMS verification.To evaluate the vibration isolation performance,typical three-springs quasi-zero stiffness(TS QZS)system is selected to compare with the proposed bionic structure.And the graphical processing unit(GPU)parallel technology is applied to perform necessary two-parameter analyses,providing more insights into the effects of parameters on the transmissibility.It is shown that the proposed structure can show advantages over the typical TS QZS system in a wider vibration isolation range for harmonic excitation case and shorter decay time for the impact excitation case.
