Problem 1 (65 pts, suggested time 50 mins). An elastic string of constant line tension¹ T is pinned at x = 0 and x = L. A constant distributed vertical force per unit length p (with units N/m) is applied to the string. Under this force, the string deflects by an amount v(x) from its undeformed (horizontal) state, as shown in the figure below. р v(x) X L The PDE describing mechanical equilibrium for the string is d dv dx dx - p=0. (1) (a) [5pts] Identify the BCs for the string and identify their type (essential/natural). Write down the strong-form BVP for the string, including PDE and BCs. (b) [10pts] Find the analytical solution of the BVP in (a). Compute the exact deflection of the midpoint v(L/2). (c) [15pts] Derive the weak-form BVP. (d) [5pts] What is the minimum number of linear elements necessary to compute the de- flection of the midpoint? (e) [15pts] Write down the element stiffness matrix and the element force vector for each element.
Problem 1 (65 pts, suggested time 50 mins). An elastic string of constant line tension1
T is pinned at x = 0 and x = L. A constant distributed vertical force per unit length p
(with units N/m) is applied to the string. Under this force, the string deflects by an amount
v(x) from its undeformed (horizontal) state, as shown in the figure below.
The PDE describing
d
dx
T
dv
dx
− p = 0 . (1)
(a) [5pts] Identify the BCs for the string and identify their type (essential/natural). Write
down the strong-form BVP for the string, including PDE and BCs.
(b) [10pts] Find the analytical solution of the BVP in (a). Compute the exact deflection
of the midpoint v(L/2).
(c) [15pts] Derive the weak-form BVP.
(d) [5pts] What is the minimum number of linear elements necessary to compute the deflection of the midpoint?
(e) [15pts] Write down the element stiffness matrix and the element force
element.
![Problem 1 (65 pts, suggested time 50 mins). An elastic string of constant line tension¹
T is pinned at x = 0 and x = L. A constant distributed vertical force per unit length p
(with units N/m) is applied to the string. Under this force, the string deflects by an amount
v(x) from its undeformed (horizontal) state, as shown in the figure below.
р
v(x)
X
L
The PDE describing mechanical equilibrium for the string is
d dv
dx
dx
- p=0.
(1)
(a) [5pts] Identify the BCs for the string and identify their type (essential/natural). Write
down the strong-form BVP for the string, including PDE and BCs.
(b) [10pts] Find the analytical solution of the BVP in (a). Compute the exact deflection
of the midpoint v(L/2).
(c) [15pts] Derive the weak-form BVP.
(d) [5pts] What is the minimum number of linear elements necessary to compute the de-
flection of the midpoint?
(e) [15pts] Write down the element stiffness matrix and the element force vector for each
element.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F44771ccb-18ef-4ee9-9657-f17f9fc0e809%2F25dbd6f8-8ece-4405-853d-c74d813fe1d5%2Fpogxm5q_processed.jpeg&w=3840&q=75)

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