The deployable mechanisms consisting of square units are widely applied in aeronautics and astronautics,biomedicine, architecture and other fields, and joint clearance in such a mechanism is unavoidable. This study is...The deployable mechanisms consisting of square units are widely applied in aeronautics and astronautics,biomedicine, architecture and other fields, and joint clearance in such a mechanism is unavoidable. This study is carried out to accurately investigate the dynamic property of the mechanism.Firstly,a dynamics model was built by considering the motion characteristics between elements of joint with clearances. Secondly,based on Floures contact force model and LuGre friction force model,the tangential and normal contact force of revolute pair element with clearance were calculated respectively. Finally,square combined mechanisms' dynamic analytical method considering joint clearance was investigated, and constraint renege problem was resolved by adopting Baumgarte stable constraint method in integration process.Analytical result indicates that the impact of joint clearance on dynamic property of square combined mechanism should not be neglected.展开更多
The abdomen of a honeybee is a blueprint for bioinspired mechanical design because of its movement flexibility and compactness.However,the abdominal muscles closely related to the movement flexibility mechanism have n...The abdomen of a honeybee is a blueprint for bioinspired mechanical design because of its movement flexibility and compactness.However,the abdominal muscles closely related to the movement flexibility mechanism have not been fully identified,limiting the potential biological advantage of their use in bionic mechanism design.In this study,we reveal the muscle distribution of the complete muscular driving unit in a honeybee abdomen using stereoscopy and scanning electron microscopy,and the muscle distribution was effectively verified using X-ray tomography.A novel equivalent unit mechanism(EUM)was then proposed and the kinematic analysis indicated that the extension ratio,bending angle,and swing angle of the EUM reached 9.36%,1.22°,and 4.43°,respectively.The deformation ability of the EUM was consistent with the movement of the abdomen,confirming the movement flexibility.This work may provide a new perspective for distributed bionic mechanism design.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51175422)
文摘The deployable mechanisms consisting of square units are widely applied in aeronautics and astronautics,biomedicine, architecture and other fields, and joint clearance in such a mechanism is unavoidable. This study is carried out to accurately investigate the dynamic property of the mechanism.Firstly,a dynamics model was built by considering the motion characteristics between elements of joint with clearances. Secondly,based on Floures contact force model and LuGre friction force model,the tangential and normal contact force of revolute pair element with clearance were calculated respectively. Finally,square combined mechanisms' dynamic analytical method considering joint clearance was investigated, and constraint renege problem was resolved by adopting Baumgarte stable constraint method in integration process.Analytical result indicates that the impact of joint clearance on dynamic property of square combined mechanism should not be neglected.
基金We thank Mr.Yanfei Hu,Mr.Chenzhou Wang,and Ms.Chenguang Zhao,Center of Biomedical Analysis in Tsinghua University,for microstructure observation experiments about honeybee abdomen.This work was supported by the National Natural Science Foundations of China(Grant No.51475258 and 51805293)the Beijing Natural Science Foundation(Grant No.3184050)the free exploration project of State Key Laboratory of Tribology,Tsinghua University(SKLT2020B04).
文摘The abdomen of a honeybee is a blueprint for bioinspired mechanical design because of its movement flexibility and compactness.However,the abdominal muscles closely related to the movement flexibility mechanism have not been fully identified,limiting the potential biological advantage of their use in bionic mechanism design.In this study,we reveal the muscle distribution of the complete muscular driving unit in a honeybee abdomen using stereoscopy and scanning electron microscopy,and the muscle distribution was effectively verified using X-ray tomography.A novel equivalent unit mechanism(EUM)was then proposed and the kinematic analysis indicated that the extension ratio,bending angle,and swing angle of the EUM reached 9.36%,1.22°,and 4.43°,respectively.The deformation ability of the EUM was consistent with the movement of the abdomen,confirming the movement flexibility.This work may provide a new perspective for distributed bionic mechanism design.
