This study presents earthquake performance analysis of the Torul Concrete-Faced Rockfill （CFR） Dam with two-dimensional dam-soil and dam-soil-reservoir finite element models. The Lagrangian approach was used with fl...This study presents earthquake performance analysis of the Torul Concrete-Faced Rockfill （CFR） Dam with two-dimensional dam-soil and dam-soil-reservoir finite element models. The Lagrangian approach was used with fluid elements to model impounded water. The interface elements were used to simulate the slippage between the concrete face slab and the rockfill. The horizontal component of the 1992 Erzincan earthquake, with a peak ground acceleration of 0.515g, was considered in time-history analysis. The Drucker-Prager model was preferred in nonlinear analysis of the concrete slab, rockfill and foundation soil. The maximum principal stresses and the maximum displacements in two opposite directions were compared by the height of the concrete slab according to linear time-history analysis to reveal the effect of reservoir water. The changes of critical displacements and principal stresses with time are also shown in this paper. According to linear and nonlinear time-history analysis, the effect of the reservoir water on the earthquake performance of the Torul CFR Dam was investigated and the possible damage situation was examined. The results show that the hydrodynamic pressure of reservoir water leads to an increase in the maximum displacements and principal stresses of the dam and reduces the earthquake performance of the dam. Although the linear time-history analysis demonstrates that the earthquake causes a momentous damage to the concrete slab of the Torul CFR Dam, the nonlinear time-history analysis shows that no evident damage occurs in either reservoir case.展开更多
Parallel robotic mechanisms have emerged as a vital subfield in robotics science and engineering over the past few decades,receiving widespread attention and undergoing significant advancements.Despite extensive resea...Parallel robotic mechanisms have emerged as a vital subfield in robotics science and engineering over the past few decades,receiving widespread attention and undergoing significant advancements.Despite extensive research encompassing type synthesis,dimension optimization,control theory,design principles,manufacturing techniques,and others,comprehensive reviews on the motion–force-related performance of parallel robotic mechanisms and their applications to real-world problems are still lacking.This review aims to fill this gap by analyzing and summarizing significant studies on the motion–force interaction performance of parallel robotic mechanisms.Examining the historical development of theoretical paradigms,the research of parallel robotic mechanisms began relatively late compared with their serial counterparts.Initially,approaches for parallel mechanisms were inherited or adopted from serial mechanisms.However,many cases have demonstrated that parallel robotic mechanisms possess unique characteristics,making it infeasible to directly transfer the theories developed for serial mechanisms to parallel mechanisms.Therefore,new methodologies are needed to properly analyze and evaluate the intrinsic properties of parallel robotic mechanisms,where the interaction between motion and force plays a crucial role.This paper offers an extensive and systematic review of the existing journal literature that analyzes and evaluates motion–force interaction performance of parallel robotics mechanisms,also known as motion/force transmission and constraint performance,providing a broad and detailed bibliography that will serve as a reference for the research community.The work examines research strategies,evaluation methods,performance indices,and real-world applications concerning the motion–force interaction performance of parallel robotic mechanisms,offering a foundation to stimulate future research and innovation.展开更多
文摘This study presents earthquake performance analysis of the Torul Concrete-Faced Rockfill （CFR） Dam with two-dimensional dam-soil and dam-soil-reservoir finite element models. The Lagrangian approach was used with fluid elements to model impounded water. The interface elements were used to simulate the slippage between the concrete face slab and the rockfill. The horizontal component of the 1992 Erzincan earthquake, with a peak ground acceleration of 0.515g, was considered in time-history analysis. The Drucker-Prager model was preferred in nonlinear analysis of the concrete slab, rockfill and foundation soil. The maximum principal stresses and the maximum displacements in two opposite directions were compared by the height of the concrete slab according to linear time-history analysis to reveal the effect of reservoir water. The changes of critical displacements and principal stresses with time are also shown in this paper. According to linear and nonlinear time-history analysis, the effect of the reservoir water on the earthquake performance of the Torul CFR Dam was investigated and the possible damage situation was examined. The results show that the hydrodynamic pressure of reservoir water leads to an increase in the maximum displacements and principal stresses of the dam and reduces the earthquake performance of the dam. Although the linear time-history analysis demonstrates that the earthquake causes a momentous damage to the concrete slab of the Torul CFR Dam, the nonlinear time-history analysis shows that no evident damage occurs in either reservoir case.
基金supported by the National Natural Science Foundation of China(Grant No.52105026).
文摘Parallel robotic mechanisms have emerged as a vital subfield in robotics science and engineering over the past few decades,receiving widespread attention and undergoing significant advancements.Despite extensive research encompassing type synthesis,dimension optimization,control theory,design principles,manufacturing techniques,and others,comprehensive reviews on the motion–force-related performance of parallel robotic mechanisms and their applications to real-world problems are still lacking.This review aims to fill this gap by analyzing and summarizing significant studies on the motion–force interaction performance of parallel robotic mechanisms.Examining the historical development of theoretical paradigms,the research of parallel robotic mechanisms began relatively late compared with their serial counterparts.Initially,approaches for parallel mechanisms were inherited or adopted from serial mechanisms.However,many cases have demonstrated that parallel robotic mechanisms possess unique characteristics,making it infeasible to directly transfer the theories developed for serial mechanisms to parallel mechanisms.Therefore,new methodologies are needed to properly analyze and evaluate the intrinsic properties of parallel robotic mechanisms,where the interaction between motion and force plays a crucial role.This paper offers an extensive and systematic review of the existing journal literature that analyzes and evaluates motion–force interaction performance of parallel robotics mechanisms,also known as motion/force transmission and constraint performance,providing a broad and detailed bibliography that will serve as a reference for the research community.The work examines research strategies,evaluation methods,performance indices,and real-world applications concerning the motion–force interaction performance of parallel robotic mechanisms,offering a foundation to stimulate future research and innovation.
