Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSM...Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSME spring can contract upon heating and extend uponcooling. The results show that there is an increase of the recovery ratio up to a maximum TWSME of45%. During the training procedure, transformation temperatures and hysteresis were measured bydifferent scanning calorimetry (DSC). The results show that A_s (reverse transformation starttemperature) and A_f (reverse transformation finish temperature) shift to lower temperature aftertraining. The intervals of A_fA_s and M_s-M_f (M_s and M_f are the martensite start and finishtemperatures, respectively) increase and the heat of transformation decreases after training. Theelectrothermal driving characteristics of the TWSME springs were also investigated with alternatingcurrent density of 3.2-14.7 A/mm^2. It is found that the time response and the maximum contractionratio greatly depend on the magnitude of the electrical current density.展开更多
On the basis of analyzing the system constitution of tracked vehicle semi-active suspension, which consists of electrorheological （ER） damper and shape memory alloy （SMA） spring, a seven degree of freedom （7-DOF...On the basis of analyzing the system constitution of tracked vehicle semi-active suspension, which consists of electrorheological （ER） damper and shape memory alloy （SMA） spring, a seven degree of freedom （7-DOF） dynamic model is established. The change of the elasticity of SMA spring and the characteristics of the ER shock absorber are studied. In addition, the study about fuzzy control logic is also carried out. Simulation of a C grade road under random excitations and definite disturbances is performed. Simulation result shows the fuzzy control strategy, which is used in the control of semi-active suspension system with ER damper and SMA springs, is effective, stable and reliable.展开更多
It is well-known that suspension systems plays a major role in automotive technology.Most of the today’s vehicle applies a passive suspension systems consisting of a spring and damper.The design of automotive suspens...It is well-known that suspension systems plays a major role in automotive technology.Most of the today’s vehicle applies a passive suspension systems consisting of a spring and damper.The design of automotive suspension have been a compromise between passenger comfort,suspension travel and road holding ability.This work aims in reducing the suspension travel alone by developing a quarter car model suspension for a passenger car to improve its performance by introducing shape memory alloy spring(Nitinol)instead of traditional spring.A two way shape memory alloy spring possesses two different stiffness in its two different phases(martensite and austenite).In this study,road profile is considered as a simple harmonic profile and vibration analysis of aminiature quarter car model suspension system has been carried out experimentally.Using theoretical method,the displacement of the sprung mass is also studied and discussed.The vibration analysis have been carried out for the suspension system at both phases of the spring and the results gives a significant improvement in reducing the displacement of sprung mass for various excitation frequencies.展开更多
基金This project is financially supported by the National Natural Science Foundation of China (No. 10175042)
文摘Two-way shape memory effect (TWSME) was induced into the TiNi shape memoryalloys (SMAs) spring by thermomechanical training after annealing treatment, which has promisingapplication in micro-actuating fields. The TWSME spring can contract upon heating and extend uponcooling. The results show that there is an increase of the recovery ratio up to a maximum TWSME of45%. During the training procedure, transformation temperatures and hysteresis were measured bydifferent scanning calorimetry (DSC). The results show that A_s (reverse transformation starttemperature) and A_f (reverse transformation finish temperature) shift to lower temperature aftertraining. The intervals of A_fA_s and M_s-M_f (M_s and M_f are the martensite start and finishtemperatures, respectively) increase and the heat of transformation decreases after training. Theelectrothermal driving characteristics of the TWSME springs were also investigated with alternatingcurrent density of 3.2-14.7 A/mm^2. It is found that the time response and the maximum contractionratio greatly depend on the magnitude of the electrical current density.
基金Sponsored by the Ministerial Level Foundation (405020104)
文摘On the basis of analyzing the system constitution of tracked vehicle semi-active suspension, which consists of electrorheological （ER） damper and shape memory alloy （SMA） spring, a seven degree of freedom （7-DOF） dynamic model is established. The change of the elasticity of SMA spring and the characteristics of the ER shock absorber are studied. In addition, the study about fuzzy control logic is also carried out. Simulation of a C grade road under random excitations and definite disturbances is performed. Simulation result shows the fuzzy control strategy, which is used in the control of semi-active suspension system with ER damper and SMA springs, is effective, stable and reliable.
文摘It is well-known that suspension systems plays a major role in automotive technology.Most of the today’s vehicle applies a passive suspension systems consisting of a spring and damper.The design of automotive suspension have been a compromise between passenger comfort,suspension travel and road holding ability.This work aims in reducing the suspension travel alone by developing a quarter car model suspension for a passenger car to improve its performance by introducing shape memory alloy spring(Nitinol)instead of traditional spring.A two way shape memory alloy spring possesses two different stiffness in its two different phases(martensite and austenite).In this study,road profile is considered as a simple harmonic profile and vibration analysis of aminiature quarter car model suspension system has been carried out experimentally.Using theoretical method,the displacement of the sprung mass is also studied and discussed.The vibration analysis have been carried out for the suspension system at both phases of the spring and the results gives a significant improvement in reducing the displacement of sprung mass for various excitation frequencies.
