图1图2图3三幅图的matlab绘图指令图1的matlab绘图指令C=[0,0];B=[600/2,-600*sqrt(3)/2];plot([C(1),B(1)],[C(2),B(2)],'k-'),hold onaxis equalD=[B(1)-B(2),0];plot([D(1),B(1)],[D(2),B(2)],'k-'),hold onplot([C(1)-50,D(1)+50],[C(2),D(2)],'k-','LineWidth',2),hold onn=20;yinying=zeros(2,n+1);yinying(1,1:n+1)=(C(1)-50):((D(1)+50)-(C(1)-50))/n:(D(1)+50);yinying(2,1:n+1)=zeros(1,n+1);yinying(3,1:n+1)=yinying(1,1:n+1)+20*ones(1,n+1);yinying(4,1:n+1)=yinying(2,1:n+1)+20*ones(1,n+1);for ii=1:n+1plot([yinying(1,ii),yinying(3,ii)],[yinying(2,ii),yinying(4,ii)],'k-'),hold on endplot(C(1),C(2),'k-', 'Marker','.','MarkerSize',15)plot(B(1),B(2),'k.', 'Marker','.','MarkerSize',15)plot(D(1),D(2),'k.', 'Marker','.','MarkerSize',15)text(C(1)-30,C(2)-20,'C');text(B(1)+20,B(2),'B');text(D(1)+10,D(2)-20,'D');text(B(1)+20,B(2)-200,'P','FontWeight','Bold');text(C(1)-100,C(2)-100,'L_{BC}=600mm');text(B(1)-100,B(2)+200,'\alpha=30^{。

}');text(B(1)+50,B(2)+180,'\beta=45^{。

}');plot([B(1),B(1)],[B(2),B(2)+200],'k-.'),hold onplot([B(1),B(1)],[B(2),B(2)-200],'k-','LineWidth',1.5),hold onarrow_P=[B(1),B(1)+8,B(1)-11;B(2)-200,B(2)-200+30,B(2)-200+30];fill(arrow_P(1,:),arrow_P(2,:),'k')axis([-200,1000,-800,100])theta=90:(120-90)/30:120;theta=theta*pi/180;r=100;x0=B(1);y0=B(2);x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-'),hold ontheta=45:(120-90)/45:90;theta=theta*pi/180;r=150;x0=B(1);y0=B(2);x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-'),hold onbox off图2的matlab绘图指令为% cantilever_beam 绘图clear allA=[0,-10];B=[0,10];C=[50,-10];D=[50,10];plot([A(1),C(1)],[A(2),C(2)],'k-','LineWidth',1.5),hold onplot([B(1),D(1)],[B(2),D(2)],'k-','LineWidth',1.5),hold onplot([D(1),C(1)],[D(2),C(2)],'k-','LineWidth',1.5),hold onplot([A(1),B(1)],[A(2)-10,B(2)+10],'k-','LineWidth',1.5),hold on axis equalE=[0,0];F=[100,0];plot([E(1),F(1)],[E(2),F(2)],'k-.'),hold onG=[50,-5];H=[50,5];K=[100,-5];L=[100,5];plot([G(1),K(1)],[G(2),K(2)],'k-','LineWidth',1.5),hold onplot([H(1),L(1)],[H(2),L(2)],'k-','LineWidth',1.5),hold onplot([K(1),L(1)],[K(2),L(2)],'k-','LineWidth',1.5),hold onplot([C(1),C(1)],[C(2),C(2)-10],'k-','LineWidth',1),hold onplot([K(1),K(1)],[K(2),K(2)-15],'k-','LineWidth',1),hold onplot([0,22],[-15,-15],'k-','LineWidth',1),hold onplot([28,72],[-15,-15],'k-','LineWidth',1),hold onplot([78,100],[-15,-15],'k-','LineWidth',1),hold onarrow_P=[0+4,0,0+4;-15-1,-15,-15+1];fill(arrow_P(1,:),arrow_P(2,:),'k')arrow_P=[50-4,50,50-4;-15-1,-15,-15+1];fill(arrow_P(1,:),arrow_P(2,:),'k')arrow_P=[50+4,50,50+4;-15-1,-15,-15+1];fill(arrow_P(1,:),arrow_P(2,:),'k')arrow_P=[100-4,100,100-4;-15-1,-15,-15+1];fill(arrow_P(1,:),arrow_P(2,:),'k')plot([F(1),F(1)+15],[F(2),F(2)],'k-','LineWidth',1),hold onarrow_P=[F(1)+11,F(1)+15,F(1)+11;F(2)-1,F(2),F(2)+1];fill(arrow_P(1,:),arrow_P(2,:),'k')n=30;yinying=zeros(4,n+1);yinying(1,1:n+1)=zeros(1,n+1);yinying(2,1:n+1)=(A(2)-10):(((B(2)+10))-(A(2)-10))/n:(B(2)+10);yinying(3,1:n+1)=yinying(1,1:n+1)-3*ones(1,n+1);yinying(4,1:n+1)=yinying(2,1:n+1)+3*ones(1,n+1);for ii=1:n+1plot([yinying(1,ii),yinying(3,ii)],[yinying(2,ii),yinying(4,ii)],'k-'),hold on endplot(E(1),E(2),'k-', 'Marker','.','MarkerSize',15)plot(F(1),F(2),'k.', 'Marker','.','MarkerSize',15)plot(50,0,'k.', 'Marker','.','MarkerSize',15)text(25,13,'I_{1}','fontname','华文仿宋','FontAngle','italic');text(75,8,'I_{2}','fontname','华文仿宋','FontAngle','italic');text(101,18,'P','FontWeight','Bold');text(116,0,'x');text(0,33,'y');text(E(1)+1,E(2)-2.5,'1');text(50+1,0-2.5,'2');text(F(1)+1,F(2)-2.5,'3');z=text(24,-15,'$$\frac{L}{2}$$');set(z,'Interpreter','latex');z=text(74,-15,'$$\frac{L}{2}$$');set(z,'Interpreter','latex');plot([B(1),B(1)],[B(2)+10,B(2)+20],'k-','LineWidth',1),hold onarrow_P=[B(1)-1,B(1),B(1)+1;B(2)+16,B(2)+20,B(2)+16];fill(arrow_P(1,:),arrow_P(2,:),'k')plot([L(1),L(1)],[L(2),L(2)+20],'k-','LineWidth',1.5),hold onarrow_P=[L(1)-1,L(1),L(1)+1;L(2)+4,L(2),L(2)+4];fill(arrow_P(1,:),arrow_P(2,:),'k')plot([F(1),F(1)+15],[F(2),F(2)],'k-','LineWidth',1),hold onarrow_P=[F(1)+11,F(1)+15,F(1)+11;F(2)-1,F(2),F(2)+1];fill(arrow_P(1,:),arrow_P(2,:),'k')axis([-10,130,-35,40])box off图3的matlab绘图指令为% thin_slab 绘图P1=[0,0];P2=[0,40];P3=[50,20];P4=[100,0];P5=[100,40];plot([P1(1),P2(1)],[P1(2),P2(2)],'k-','LineWidth',1.5),hold onplot([P1(1),P4(1)],[P1(2),P4(2)],'k-','LineWidth',1.5),hold onplot([P5(1),P4(1)],[P5(2),P4(2)],'k-','LineWidth',1.5),hold onplot([P5(1),P2(1)],[P5(2),P2(2)],'k-','LineWidth',1.5),hold onplot([P5(1),P1(1)],[P5(2),P1(2)],'k-','LineWidth',1.5),hold onplot([P2(1),P4(1)],[P2(2),P4(2)],'k-','LineWidth',1.5),hold onplot(P1(1),P1(2),'k-', 'Marker','.','MarkerSize',15)plot(P2(1),P2(2),'k-', 'Marker','.','MarkerSize',15)plot(P3(1),P3(2),'k-', 'Marker','.','MarkerSize',15)plot(P4(1),P4(2),'k-', 'Marker','.','MarkerSize',15)plot(P5(1),P5(2),'k-', 'Marker','.','MarkerSize',15)plot([P1(1)+2,P1(1)+2],[P1(2),P1(2)-4],'k-','LineWidth',1.5),hold on plot([P1(1)-2,P1(1)-2],[P1(2),P1(2)-4],'k-','LineWidth',1.5),hold on plot([P1(1)-6,P1(1)+6],[P1(2)-4,P1(2)-4],'k-','LineWidth',1.5),hold on n=8;yinying=zeros(2,n+1);yinying(1,1:n+1)=(P1(1)-6):((P1(1)+6)-(P1(1)-6))/n:(P1(1)+6);yinying(2,1:n+1)=(P1(2)-4)*ones(1,n+1);yinying(3,1:n+1)=yinying(1,1:n+1)-3*ones(1,n+1);yinying(4,1:n+1)=yinying(2,1:n+1)-3*ones(1,n+1);for ii=1:n+1plot([yinying(1,ii),yinying(3,ii)],[yinying(2,ii),yinying(4,ii)],'k-'),hold on endtheta=0:(180-0)/180:180;theta=theta*pi/180;r=2;x0=P1(1);y0=P1(2);x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-','LineWidth',1.5),hold onplot([P4(1)+2,P4(1)+2],[P4(2),P4(2)-4],'k-','LineWidth',1.5),hold onplot([P4(1)-2,P4(1)-2],[P4(2),P4(2)-4],'k-','LineWidth',1.5),hold onplot([P4(1)-6,P4(1)+6],[P4(2)-4,P4(2)-4],'k-','LineWidth',1.5),hold onplot([P4(1)-7,P4(1)+7],[P4(2)-4-2,P4(2)-4-2],'k-','LineWidth',1.5),hold on n=8;yinying=zeros(2,n+1);yinying(1,1:n+1)=(P4(1)-6):((P4(1)+6)-(P4(1)-6))/n:(P4(1)+6);yinying(2,1:n+1)=(P4(2)-4-2)*ones(1,n+1);yinying(3,1:n+1)=yinying(1,1:n+1)-3*ones(1,n+1);yinying(4,1:n+1)=yinying(2,1:n+1)-3*ones(1,n+1);for ii=1:n+1plot([yinying(1,ii),yinying(3,ii)],[yinying(2,ii),yinying(4,ii)],'k-'),hold on endtheta=0:(180-0)/180:180;theta=theta*pi/180;r=2;x0=P4(1);y0=P4(2);x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-','LineWidth',1.5),hold ontheta=0:(360-0)/360:360;theta=theta*pi/180;r=1;x0=P4(1);y0=P4(2)-5;x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-','LineWidth',1.5),hold onx0=P4(1)-3;y0=P4(2)-5;x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-','LineWidth',1.5),hold onx0=P4(1)+3;y0=P4(2)-5;x=x0+r*cos(theta);y=y0+r*sin(theta);plot(x,y,'k-','LineWidth',1.5),hold onplot([P5(1),P5(1)],[P5(2),P5(2)+15],'k-','LineWidth',1.8),hold onplot([P5(1),P5(1)+13],[P5(2),P5(2)],'k-','LineWidth',1.8),hold ontext(P1(1)+1,P1(2)+3,'1');text(P2(1),P2(2)+3,'2');text(P3(1),P3(2)+3,'3');text(P4(1)-3,P4(2)+3,'4');text(P5(1)-3,P5(2)-5,'5');text(50,10,'A');text(75,20,'B');text(50,30,'C');text(25,20,'D');text(P5(1)+1,P5(2)+8,'P_{y}','FontWeight','Bold');text(P5(1)+15+1,P5(2),'P_{x}','FontWeight','Bold');text(50,0-3,'w');text(0-4,20,'h');arrow_P=[P5(1)-1,P5(1),P5(1)+1;P5(2)+4,P5(2),P5(2)+4];fill(arrow_P(1,:),arrow_P(2,:),'k')arrow_P=[P5(1)+15-4,P5(1)+15,P5(1)+15-4;P5(2)-1,P5(2),P5(2)+1]; fill(arrow_P(1,:),arrow_P(2,:),'k')axis equalaxis([-15,125,-15,60])。