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用MATLAB自带卷积分函数计算弹性半空间在一三角脉冲荷载下自由表面的竖向位移,与文献正确结果相差10的5次方倍,但自己编写卷积分代码,反而得到文献结果。请大家帮我看下问题出在哪?谢谢! ,>6mc=p Q{hK+z`D 另外,为何MATLAB自带卷积分函数结果矩阵的维数会是被卷积两矩阵维数之和减1? Ornm3%p+e SM}&
@cJ 1. 问题描述,如下图1所示: 7vqE@;:dt b^Do[o}5 j97c@ CJ;D&qo 2. 格林函数,如下图2所示: ylmVmHmc AWZ4h,as{ 2 $Z4 >! *XXa9z 3. 参考文献正确解,如下图3所示: en MHKN g [c>YKN2qa <t *3w ,=6;dT 4. 本人直接用自编卷积分MATLAB代码算的出解(如下图4)及相应代码: Si;eBPFH o>M&C
X+j$ `?N|{kb <l)I%1T_c clear; G!GGT?J clc; CfLPs)\ACm !;PKx]/& %loading history (.M &nN'Ce )q+;+J`> dt=0.01; Yu%ZwTvw ti=0.0008; yV@~B;eW0 te=12; (Sj?BZjC t=ti:dt:te;
4m9]d) pt=(10*t./1.5).*(t>=0 & t<=1.5)+(20-10*t./1.5).*(t>1.5 & t<=3)+0.*(t>3); %Y].i/".;P m=length(pt); n\scOM)3 i/DUB<>p6 %load distribution in space F-?s8RD !"^//2N+, rp=0.1; orF8% ri=0; 0bIhP,4&
rc=0.1; 9H%L;C5< dr=0.001; d_Y7/_i r=ri:dr:rc; }!vJ+ pr=1*(r<=rp)+0*(r>rp); "CQ:<$|$ n=length(pr); [{-;cpM\ DTV"~>@ %load function with respect to t and r b;e*`f8T3c Gy[m4n~Z5 p=pr.'*pt; ]\%u9,b%! "IdN *K %green's function \R#OJ=F )e\IdKl= G=1; n ^C"v6X
cs=1; SnW>` for i=1:1:m OEgp!J for j=1:1:n mvW,nM1Y u(j,i)=heaviside(cs*t(i)-r(j))/(pi*G*sqrt(t(i)^2-(r(j)/cs)^2)); p?sC</R end ON3~!Q) end 7NfA)$ xCiq;FFR %convolution and response of displacement =qTmFszT &Sp2['a! for i=1:1:m RS[QZOoW} for j=1:1:n +,ZQ(
ZW v(j,i)=0; w`K=J!5y2g for k=1:1:i n|I5ylt for g=1:1:j }7|UA%xz v(j,i)=v(j,i)+p(g,k)*u(j-g+1,i-k+1)*dr*dt; eN]9=Y~-K end; PeB7Q=d)K1 end; #ANbhHG end; 1lQO`CmR6M end; 4] I7t b\Gw|?Rv %plot the response history ]EPFyVt~3 Dj@7vM%_ plot(t,v(n,); ;bt%TxuKb xlabel('t/s'); D~JrO]mi ylabel('v/m'); Sy`7 })[ grid on; 3 At%TA: title('response of point A or C'); niJtgK:H^ <-m[0zgq 5. 直接用MATLAB自带卷积分算的出解(如下图5)及相应代码: <MBpV^Y} ;V\l,
u jAb R[QR1% q*4=sf,> clear; z7g=L@ clc; 4XXuj <2>Qr(bb %loading history gCY%@?YyN .:=G=v=1 dt=0.01; =L&}&pT ti=0.0008; <C,lHt te=12; 5ki<1{aVtZ t=ti:dt:te; <mdHca pt=(10*t./1.5).*(t>=0 & t<=1.5)+(20-10*t./1.5).*(t>1.5 & t<=3)+0.*(t>3); $4a;R I m=length(pt); i_6 Y6 6#/v:;bF %load distribution in space 8!(09gW'> K_sHZ rp=0.1; yJAz#~PO/ ri=0; S
7 *LV; rc=0.1; GY,HEe]2r dr=0.001; 3=~0m r=ri:dr:rc; m3E`kW| pr=1*(r<=rp)+0*(r>rp); Dm0Ts~ n=length(pr); YRm6~c V*w~Sr% %load function with respect to t and r -kz9KGkPb+ $,9A?' p=pr.'*pt; .8EaFEd SV0h'd(b %green function U^.kp#x# 2Ub!wee G=1; Xe7/ cs=1; Gm2q`ki for i=1:1:m #.^A5`k for j=1:1:n %DR8M\d1~H u(j,i)=heaviside(cs*t(i)-r(j))/(pi*G*sqrt(t(i)^2-(r(j)/cs)^2)); ic(`E v end hYS}PE end )UgLs|G~ yO`HL'SMo %convolution and response of displacement {WoS&eL 6wY6*R v=conv2(u,p); p,K]`pt= 51&K %plot the response history tlJ@@v&= q71~Y:7f rr=r(n); TtKV5 [tpu,rpu]=meshgrid(ti:dt:2*te-dt,ri:dr:2*rc); \hr2#! [X,Y,Z]=meshgrid(linspace(min(tpu(),max(tpu()),linspace(min(rpu(),max(rpu()),linspace(min(v(),max(v())); qPG>0
O V=Y; _8I\! h=contourslice(X,Y,Z,V,tpu,rpu,v,[0 0]+rr); /pS Y ~* set(h,'edgecolor','k'); Uop`) contourslice(X,Y,Z,V,tpu,rpu,v,[0 0]+rr); Ods/1 KW xlabel('t/s'); oW
\k%Vj ylabel('r/m'); l" P3lKS zlabel('v/m'); vlS+UFH0 axis([0 12 0 0.1 0 12e4]); (AI
4a+ view(0,0); ;*}tbh3;. grid on; he\ pW5p title('displacement response history of point A or C');
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