modeling of truss using piezoelectric elements
function [m,k,d,rdof]=modeling(N)
E=7.27e10;
A=6.283e-5;
density=3.1e3;
%N:桁架单元的个数
l=0.4;
%l:横杆的长度
m_joint=0.4;
%节点质量
node_number=4*N+4;
elment_number=13*N+5;
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001195s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.132595s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001051s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001136s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001050s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003138s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000947s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.005633s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.024689s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001790s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 24864 [ RunTime:0.012605s ]
