This paper presents a comparison study of workspace and dexterity of two Tricept units for Reconfigurable Parallel Kinematic Machines （RPKMs）. The modular leg of RPKMs is designed and the RPKMs can be built by chang...This paper presents a comparison study of workspace and dexterity of two Tricept units for Reconfigurable Parallel Kinematic Machines （RPKMs）. The modular leg of RPKMs is designed and the RPKMs can be built by changing tile setting of modules. A compositive kinematic model is developed accordingly. The inverse kinematics and Jacobian of these two Trieept units are analyzed. Considering workspaee volume and dexterity, the effeets of geometric size of some modules on the two Trieept units are discussed. In the end, comparison results of these two Tricept units are. given. The eomparison of two kinds of Parallel Kinematic Machines （PKMs） can be of help in the design and configuration planning of the RPKMs.展开更多
Numerical simulations of the deep roadway were carried out through application of the strain-softening constitutive model. Differences between the deep and shallow roadway of the rock bearing structure were analyzed. ...Numerical simulations of the deep roadway were carried out through application of the strain-softening constitutive model. Differences between the deep and shallow roadway of the rock bearing structure were analyzed. Influences of the supporting resistance on the rock bearing structure at the deep roadway were discussed. The results show that there is alternation of strong and weak strength-softening region in the surrounding rock of deep roadway. However, the increase in the supporting resistance cuts down the size of strength-softening region of surrounding rock, decreases its strength-softening degree, and im- proves the stress distribution condition of the surrounding rock mass. It is concluded that the supporting resistance can raise the self-supporting ability of surrounding rock through controlling its strength-softening so as to make the rock bearing structure of deep roadway stable.展开更多
文摘This paper presents a comparison study of workspace and dexterity of two Tricept units for Reconfigurable Parallel Kinematic Machines （RPKMs）. The modular leg of RPKMs is designed and the RPKMs can be built by changing tile setting of modules. A compositive kinematic model is developed accordingly. The inverse kinematics and Jacobian of these two Trieept units are analyzed. Considering workspaee volume and dexterity, the effeets of geometric size of some modules on the two Trieept units are discussed. In the end, comparison results of these two Tricept units are. given. The eomparison of two kinds of Parallel Kinematic Machines （PKMs） can be of help in the design and configuration planning of the RPKMs.
文摘Numerical simulations of the deep roadway were carried out through application of the strain-softening constitutive model. Differences between the deep and shallow roadway of the rock bearing structure were analyzed. Influences of the supporting resistance on the rock bearing structure at the deep roadway were discussed. The results show that there is alternation of strong and weak strength-softening region in the surrounding rock of deep roadway. However, the increase in the supporting resistance cuts down the size of strength-softening region of surrounding rock, decreases its strength-softening degree, and im- proves the stress distribution condition of the surrounding rock mass. It is concluded that the supporting resistance can raise the self-supporting ability of surrounding rock through controlling its strength-softening so as to make the rock bearing structure of deep roadway stable.
