Static characteristic analysis of equivalent spring element of the triangle constant element

constant element Hong-Ye Su , YangZhao , GeTian 3,c ,Feng Shen 4,d ,Sheng-Jun Zhang 5,e , Xiang-Rong Fu 1 Department of civil Engineering, China Agricultural University, Beijing, 100083 China 2 China Nuclear Power Engineering Co., Ltd., Beijing, 100840 China 3 Department of civil Engineering, China Agricultural University, Beijing, 100083 China 4 State power investment central research institute , Beijing, 102209 China 5 State power investment central research institute., Beijing, 102209 China 6 Department of civil Engineering, China Agricultural University, Beijing, 100083 China Suhy@cau.edu.cn, zhaoyang@cnpe.cc, tracytiange@163.com,shenfeng@snptc.com.cn, zhangshengjun@snptc.com.cn,fuxr@cau.edu.cn