A compact 3D block cutting and contact searching algorithm  

作　　者：LIN XingChao LI Xu WANG XiaoGang WANG YuJie 

机构地区：[1]State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Beijing 10003& China [2]Key Laboratory of Urban Underground Engineering of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China [3]Department of Geotechnical Engineering, China Institute of Water Resources and Hydropower Research, Beijing 100048, China

出　　处：《Science China(Technological Sciences)》2019年第8期1438-1454,共17页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 51479001, 41471052);the China Institute of Water Resources and Hydropower Research Research & Development Support Program(Grant Nos. GE0145B462017, GE0145B692017)

摘　　要：The geometry relation and the contact point-pairs detection between two three dimensional(3D) objects with arbitrary shapes are essential problems involved in discontinuous computation and computational geometry. This paper reported a geometry relation judgment and contact searching algorithm based on Contact Theory. A contact cover search algorithm is proposed to find all the possible contact cover between two blocks. Two blocks can come to contact only on these covers. Each contact cover can define a possible contact point-pair between two blocks. Data structure and flow chart are provided, as well as some examples in details.Contact problems involving concave blocks or parallel planes are considered to be very difficult in past and are solved by this algorithm. The proposed algorithm is compacted and applicable to the discontinuous computation, such as robotic control, rock mass stability, dam stability etc. A 3D cutting and block searching algorithm is also proposed in this study and used to search the outer boundary of the 3D entrance block when 3D concave blocks are encountered. The 3D cutting and block searching algorithm can be also used to form the block system for jointed rock.The geometry relation and the contact point-pairs detection between two three dimensional(3D) objects with arbitrary shapes are essential problems involved in discontinuous computation and computational geometry. This paper reported a geometry relation judgment and contact searching algorithm based on Contact Theory. A contact cover search algorithm is proposed to find all the possible contact cover between two blocks. Two blocks can come to contact only on these covers. Each contact cover can define a possible contact point-pair between two blocks. Data structure and flow chart are provided, as well as some examples in details.Contact problems involving concave blocks or parallel planes are considered to be very difficult in past and are solved by this algorithm. The proposed algorithm is compacted and applicable to the discontinuous computation, such as robotic control, rock mass stability, dam stability etc. A 3D cutting and block searching algorithm is also proposed in this study and used to search the outer boundary of the 3D entrance block when 3D concave blocks are encountered. The 3D cutting and block searching algorithm can be also used to form the block system for jointed rock.

关 键 词：CONTACT DISCONTINUOUS computation BLOCK CUTTING computational geometry jointed ROCK COVER 

分 类 号：TH[机械工程]