solve double differentiation with two limits

6 views (last 30 days)
%% hello I am trying to solve the equation with double differentiation of M_z which is equal to w_x get the value of M_z(x) but could not solve it. Could you please help me to solve this equation. M_z(x= 0) = -150 and M_z(x= L) = 250 are given
clc;
close;
clear;
syms d_F ;
syms d_F_c;
syms dM_B;
%syms Theta_B;
syms x real;
syms u_mid;
syms u_c;
syms u_max;
syms a;
syms w_x;
syms M_z;
%syms n;
%Q = 2.5; %kip/ft
L = 30.; % ft
%a = 18; %assume maximum deflection at 15', 20'
E = 29000.*12^2; %ksi to kips/ft2
I = 1890./(12)^4; %ft^4
E_I = E.*I; %kip*ft^2;
%% deflection at mid of AB
%P = 1;
%R = 1;
%syms u_2;
%R = 1
w_x = @(x) -1*x/(L/3)*heaviside(x-L/3)*(1-heaviside(x-2*L/3));
w_x_1 = w_x(x);
eq1 = gradient(M_z(x),2) == -w_z(x);
soln1 = dsolve(eq1, M_z(0)==-150, M_z(L) == 250);
fplot(x, w_x(x), [0,L]);

Accepted Answer

VBBV
VBBV on 29 Oct 2022
Edited: VBBV on 29 Oct 2022
clc;
close;
clear;
syms d_F ;
syms d_F_c;
syms dM_B;
%syms Theta_B;
syms x real;
syms u_mid;
syms u_c;
syms u_max;
syms a;
% syms w_x;
syms M_z(x);
%syms n;
%Q = 2.5; %kip/ft
L = 30.; % ft
%a = 18; %assume maximum deflection at 15', 20'
E = 29000.*12^2; %ksi to kips/ft2
I = 1890./(12)^4; %ft^4
E_I = E.*I; %kip*ft^2;
%% deflection at mid of AB
%P = 1;
%R = 1;
%syms u_2;
%R = 1
w_x = @(x) -1*x/(L/3)*heaviside(x-L/3)*(1-heaviside(x-2*L/3));
w_x_1 = w_x(x)
w_x_1 = 
eq1 = diff(M_z(x),2) == -w_x_1
eq1 = 
soln1 = dsolve(eq1, [M_z(0)==-150, M_z(L) == 250])
soln1 = 
fplot(x, w_x(x), [0,L]); axis([0 30 -5 2])
  3 Comments
VBBV
VBBV on 29 Oct 2022
sol1 is for moment variable M_z(x) . please open a new question for your problem
Milan
Milan on 29 Oct 2022
I did it, could you please have a look?

Sign in to comment.

More Answers (0)

Categories

Find more on Symbolic Math Toolbox in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!