2D Flashcards
(9 cards)
How is N computed for a 2D 3 noded element?
The 3 terms in N are the shape functions at each node, which relate 1/2A and the x and y coordinates of the other two nodes
Why is it convenient to express the strain matrix as a vector?
It reduces the complexity of the problem while maintaining scalar invariance
What is a simple way to check the stiffness matrix of a 2D problem is correct?
All columns and rows sum to zero
If you have a 3x1 stress vector and a 2x1 normal vector, how can you compute traction?
Transform the 3x1 stress vector into a 2x2 diagonally symmetric matrix and multiply by n
How do you conventionally number nodes on a 2D element?
Anti-clockwise
What is the name of the planar assumption for converting 3D problems to 2D? What does this mean for stress in the z direction?
Thin plate assumption
Sigma zz = 0
Why is k negative in Fourier’s equation?
Heat flows from hot to cold, the opposite direction of the thermal gradient
Why do the results of FEA software look smooth even if this is not the case?
The average stress/temperature distribution over an element is displayed when the nodes are the only places it has actually been calculated
What is the vector n if normal to the line y=-x?
1/ [ 1 ]
sqrt2 [ 1 ]
