Structural design of a cartesian coordinate tooth-arrangement robot
Aiming to the problem of time-consuming and low precision of the traditional tooth-arrangement methods, a conception of a professional and miniature Cartesian coordinate type robot for tooth-arrangement was put forward in this paper. Based on the analysis of tooth-arrangement process, the design scheme of tooth-arrangement robot were determined. We also build the whole three-dimensional model of Cartesian coordinate type robot of tooth-arrangement after functional analysis of every function module of tooth-arrangement robot. Finally, the kinematics simulation analysis of robot model using ADAMS is performed, and the results indicates that it is feasible and practical to realize the scheme design and structural design of Cartesian coordinate tooth-arrangement robot.
Coordinated control and experimentation of the dental arch generator of the tooth‐arrangement robot
The traditional way of acquiring the dental arch curve form is based on manual operation, which will randomly bring numerous errors caused by human factors. The purpose of this paper is to automatically acquire the dental arch curve and implement the coordinated control of the dental arch generator of the multi‐manipulator tooth‐arrangement robot, which can be used in full denture manufacturing.
Effect of stress conditions on collapse deformation behavior of a rockfill material
A set of saturated and dry-saturated large-scale triaxial tests were conducted in order to explore the effects of stress conditions on the saturation-induced collapse deformation behavior of a rockfill material. Specimens were tested in different confining pressures and for dry-saturated tests the specimens were submerged in various shear stress levels. The results indicate that in all of the dry-saturated tests a sudden reduction in the volume of the specimens was observed during the submerging process. The ratio of the minimum axial strength of a submerged specimen (at the end of the saturation process) to the shear strength of the specimen before saturation is defined as the coefficient of stress recovery, Csr. Results of the dry-saturated tests showed that this ratio increases as the confining pressure increases and decreases by increasing the shear stress level. According to the results of dry-saturated tests the values of internal friction angle reduction caused by saturation (Δϕc), the ratio of the elasticity modulus of the material after saturation to its elasticity modulus in dry condition, i.e., Ewet/Edry, and also the saturation induced sudden volumetric strain (εvc) decrease as the confining pressure increases. However the shear stress level does not have any meaningful effect on the variation of Dfc, Ewet/Edry and (εvc).