First young people’s forum breaks new ground in China-Africa cooperation WHAT is the definition of a young leader? In Magdalene Moonsamy’s mind,young leaders are people who speak out and take active roles in society...First young people’s forum breaks new ground in China-Africa cooperation WHAT is the definition of a young leader? In Magdalene Moonsamy’s mind,young leaders are people who speak out and take active roles in society.They represent the concerns and views of their peers,concentrate on problem solving,and strive to make a difference. Moonsamy,South Africa’s Afri-展开更多
By imitating the body structure and movement mode of the crab in nature,a novel stick–slip piezo-driven positioning platform was proposed by employing the bionic flexible hinge mechanism with a symmetrical structure ...By imitating the body structure and movement mode of the crab in nature,a novel stick–slip piezo-driven positioning platform was proposed by employing the bionic flexible hinge mechanism with a symmetrical structure and two piezoelectric stacks.The structural design and bionic motion principle were discussed,followed by analyzing the feasibility,safety,and output magnification ratio of the bionic flexible hinge mechanism via the stiffness matrix method and finite element simulation.To investigate the output performances of the positioning platform,a prototype was fabricated and an experiment system was established.Stepping characteristics of the positioning platform under various driving voltages were characterized,and the results indicated that the positioning platform could move steadily under various driving voltages.Within 1 s,the differences between the forward and reverse output displacement were less than 3%under different driving frequencies,proving the high bidirectional motion symmetry.The maximum driving speed of 5.44 mm/s was obtained under the driving voltage of 120 V and driving frequency of 5 Hz.In addition,the carrying load capacity of the positioning platform was tested by standard weights,and the results showed that when the carrying load reached 10 N,the driving speed could still reach 60μm/s.展开更多
文摘First young people’s forum breaks new ground in China-Africa cooperation WHAT is the definition of a young leader? In Magdalene Moonsamy’s mind,young leaders are people who speak out and take active roles in society.They represent the concerns and views of their peers,concentrate on problem solving,and strive to make a difference. Moonsamy,South Africa’s Afri-
基金This work was supported by the National Natural Science Foundation of China(Grant No.52075221)the Research Foundation of Education Department of Jilin Province,China(Grant No.JJKH20231153KJ)the Fundamental Research Funds for the Central Universities(2019-2023).
文摘By imitating the body structure and movement mode of the crab in nature,a novel stick–slip piezo-driven positioning platform was proposed by employing the bionic flexible hinge mechanism with a symmetrical structure and two piezoelectric stacks.The structural design and bionic motion principle were discussed,followed by analyzing the feasibility,safety,and output magnification ratio of the bionic flexible hinge mechanism via the stiffness matrix method and finite element simulation.To investigate the output performances of the positioning platform,a prototype was fabricated and an experiment system was established.Stepping characteristics of the positioning platform under various driving voltages were characterized,and the results indicated that the positioning platform could move steadily under various driving voltages.Within 1 s,the differences between the forward and reverse output displacement were less than 3%under different driving frequencies,proving the high bidirectional motion symmetry.The maximum driving speed of 5.44 mm/s was obtained under the driving voltage of 120 V and driving frequency of 5 Hz.In addition,the carrying load capacity of the positioning platform was tested by standard weights,and the results showed that when the carrying load reached 10 N,the driving speed could still reach 60μm/s.
