索引超出数组范围。

clc, clear

delta_epsilon=0.01;

E=142;

a=382.6;

b=0.55;

sigma_Y=19.53;

epsilon(1)=0;

epsilon_p(1)=0;

q(1)=0;

gamma(1)=0;

for i=1:40

epsilon(i+1)=epsilon(i)+delta_epsilon;

sigma_trial(i+1)=E*(epsilon(i+1)-epsilon_p(i));

f_trial(i+1)=abs(sigma_trial(i+1))-(sigma_Y+a*(2/3)^0.5*epsilon_p(i)^b);

if f_trial(i+1)<=0

gamma(i+1)=gamma(i);

epsilon_p(i+1)=epsilon_p(i);

q(i+1)=q(i);

sigma(i+1)=sigma_trial(i+1);

elseif f_trial(i+1)>0

epsilon_p(i+1)=solve(epsilon(i+1)-epsilon_p(i+1)-(sigma_Y+a*(2/3)^0.5*epsilon_p(i+1)^b)==0,epsilon_p(i+1));

gamma(i)=1/(b*a*(2/3)^0.5*epsilon_p(i+1)^b);

sigma(i+1)=sigma_trial(i+1)-E*gamma(i);

q(i+1)=q(i)+gamma(i);

end

end

plot(epsilon,sigma)

%%加黄部分改了很多次，始终出现索引超出数组范围的情况，请大神指教，应该怎么改

Answer 1

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仅供参考，但方程求解不一定总是存在解哈

clc, clear
delta_epsilon=0.01;
E=142;
a=382.6;
b=0.55;
sigma_Y=19.53;
epsilon(1)=0;
epsilon_p(1)=0;
q(1)=0;
gamma(1)=0;


for i=1:40
    epsilon(i+1)=epsilon(i)+delta_epsilon;

    sigma_trial(i+1)=E*(epsilon(i+1)-epsilon_p(i));

    f_trial(i+1)=abs(sigma_trial(i+1))-(sigma_Y+a*(2/3)^0.5*epsilon_p(i)^b);

    if f_trial(i+1)<=0
        gamma(i+1)=gamma(i);

        epsilon_p(i+1)=epsilon_p(i);

        q(i+1)=q(i);

        sigma(i+1)=sigma_trial(i+1);
    elseif f_trial(i+1)>0
        syms x
        epsilon_p(i+1)=vpasolve(epsilon(i+1)-x-(sigma_Y+a*(2/3)^0.5*x^b)==0,x);

        gamma(i)=1/(b*a*(2/3)^0.5*epsilon_p(i+1)^b);

        sigma(i+1)=sigma_trial(i+1)-E*gamma(i);

        q(i+1)=q(i)+gamma(i);
    end
end

plot(epsilon,sigma)