Assignment 3
General Instructions
1) This assignment contains 2 problems that has to be solved using MATLAB.
2) Each problem carries 25 marks.
3) You are supposed to submit one single word file (submission in other formats will not be
accepted) which contains
I)
Hand calculation for initial instance of time (t = 0s)
II)
MATLAB code (Do not copy paste the screen shot of your code, instead copy paste
the entire code in word document)
III)
Plots and other outputs from MATLAB
4) Very Important: Write your name and roll number in your submitted file
5) Malpractice in any form (includes copying of codes and hand calculation) will attract severe
action.
Problem 1
It is given that, the truss structure as shown in Fig. 1 is able to withstand a maximum tensile and compressive
force of 5 kN and 3 kN respectively. The applied force P is a function of time (t) and the functional relation
is given by equation 1.
Fig. 1
Answer the follwing questions using Method of Joints
1) Find the maximum value of P that the structure can withstand. Also find out the time
instant at which the structure fails.
2) Identify which member is more succeptable to failure?
3) Using MATLAB, plot the variation of forces in all members with time till the structure
fails.
P = 0.1 (t+1)
(1)
Problem 2
In the following truss structure, A is a fixed support and E is a roller support. A time varying force F acts
through point D on the structure and the variation of F with time is given by the equation 2. The force F acts
at an angle θ at point D, where θ is also a function of time (t) and is given by equation 3. Using MATLAB,
plot the variation of forces in all members with time. Make use of Method of Joints to solve the problem.
(Take initial value of t=0 s, maximum value of t = 6 s and its increment is 0.5 s)
F = 8+t
(2)
θ = 15t
(3)