Essence of education is to guide. The scene teachers create is like a key to help the students feel the music, and played an active role in the teaching process immeasurably. Through multimedia assisted teaching, the ...Essence of education is to guide. The scene teachers create is like a key to help the students feel the music, and played an active role in the teaching process immeasurably. Through multimedia assisted teaching, the use of a wide range of teaching methods in music teaching, so that the children take the initiative to actively participate in musical activities to develop their musical aesthetic and correct music ability to inspire their interest in learning music, promote classroom further improve the quality of teaching.展开更多
The study of soil and rigid body system interactions is very important for the exploration of the Moon and Mars worldwide.The discrete element method(DEM)is a relatively accurate simulation method to study dry sand so...The study of soil and rigid body system interactions is very important for the exploration of the Moon and Mars worldwide.The discrete element method(DEM)is a relatively accurate simulation method to study dry sand soil mechanical properties.However,it is not suitable for bodies that are in mutual contact,connected due to constraints or have complex inertia properties due to their geometry.An efficient combination of the two-dimensional discrete element and multibody dynamic modeling method is proposed to solve the problem,in which the contacts and frictions among the granular spheres and the multibody system,including the smooth and rough rigid bodies,are taken into account.In this work,the soil field is modeled by a two-dimensional DEM,and the dynamics of the constrained rigid body system are modeled by the Cartesian method.A detection algorithm is developed to address the interactions between spherical discrete elements and roughly shaped rigid bodies.The advantage of this coupled method is that it enables the simultaneous capture of both responses.Finally,the program is verified by simulation experiments of the three-ball collision and the collision among the rectangular bars and the three balls.Based on this,the movement of the toothed wheel in the granular matter is analyzed,and the results show that the wheel with six teeth and 30°inclination has the fastest forward speed.In extraterrestrial objects,the wheel grip worsens,but the forward speed first increases and then decreases with decreasing gravity acceleration and loads on wheels,which proves that the coupled two-dimensional DEM and multibody dynamic program is effective in solving engineering problems.展开更多
文摘Essence of education is to guide. The scene teachers create is like a key to help the students feel the music, and played an active role in the teaching process immeasurably. Through multimedia assisted teaching, the use of a wide range of teaching methods in music teaching, so that the children take the initiative to actively participate in musical activities to develop their musical aesthetic and correct music ability to inspire their interest in learning music, promote classroom further improve the quality of teaching.
基金supported by the Key Program of National Natural Science Foundation of China(Grant No.11932001)the General Program of National Natural Science Foundation of China(Grant Nos.11772186 and 11772188)for which the authors are grateful.This research was also supported by the Key Laboratory of Hydrodynamics(Ministry of Education).
文摘The study of soil and rigid body system interactions is very important for the exploration of the Moon and Mars worldwide.The discrete element method(DEM)is a relatively accurate simulation method to study dry sand soil mechanical properties.However,it is not suitable for bodies that are in mutual contact,connected due to constraints or have complex inertia properties due to their geometry.An efficient combination of the two-dimensional discrete element and multibody dynamic modeling method is proposed to solve the problem,in which the contacts and frictions among the granular spheres and the multibody system,including the smooth and rough rigid bodies,are taken into account.In this work,the soil field is modeled by a two-dimensional DEM,and the dynamics of the constrained rigid body system are modeled by the Cartesian method.A detection algorithm is developed to address the interactions between spherical discrete elements and roughly shaped rigid bodies.The advantage of this coupled method is that it enables the simultaneous capture of both responses.Finally,the program is verified by simulation experiments of the three-ball collision and the collision among the rectangular bars and the three balls.Based on this,the movement of the toothed wheel in the granular matter is analyzed,and the results show that the wheel with six teeth and 30°inclination has the fastest forward speed.In extraterrestrial objects,the wheel grip worsens,but the forward speed first increases and then decreases with decreasing gravity acceleration and loads on wheels,which proves that the coupled two-dimensional DEM and multibody dynamic program is effective in solving engineering problems.
