2015/11/14 环节的频率响应一振荡环节（续） dIG(j@)1=0 E=0.05 1 do 0.20 0.25 0.3 0. 40 谐振须率 2 0.5 0,.=0vV-25 =0.707 1.00 谐振峰值 M.=A(0,)= 25V1-52 00.20.40.60.811.21.41.61.82 /①n School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 环节的频率响应一振荡环节（续） 0<0n 4L(o)=-20lg T1- (巴+(250 0. 0>0m L(w)=-20lg 1-(巴PT+(25”)?+201g(巴y O 20 0.20 025 =0.40 0.80 0 0.90 0.707 1.00 0.1 10 School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 92015/11/14 9 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 2 1 2    r n   2 1 ( ) 2 1 M A r r       谐振峰值 谐振频率 d | ( ) | 0 d G j   环节的频率响应—振荡环节（续） BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 2 2 2 ( ) 20lg [1 ( ) ] (2 ) n n L            2 2 2 2 ( ) 20lg [1 ( ) ] (2 ) 20lg( ) n n n L                 n   n 环节的频率响应—振荡环节（续）