Solid Mechanics Flashcards
How do you relate the deformation at a point given a force when the system is statically indeterminate?
- Use the strain energy equation to find U
- Draw the relationship that U=W
- W=(P*d)/2
What is the equation for the parallel axis theorem?
I=I_c + ad^2
What is the equation to find the neutral axis?
Y=summation(y_i*A_i)/Summation(A_i)
y_i*A_i=Q_i
How can you ensure a load will induce strictly bending with no twisting on a beam?
Apply the load through the shear center
How do you locate the shear center on a:
- Doubly Symmetric Shape
- Singly Symmetric Shape
- Centroid
2. On the axis of symmetry
How do you find the centroid of a composite beam?
E_1y_1A_1+E_2y_2A_2=0
where y are the distance from the ends to the neutral axis
How do you calculate the Yield moment of a beam? What is the yield moment of a beam?
M_y=sigma_y*I/y
The moment at which a beam no longer behaves linearly elastic and instead begins perfectly plastic deformation
How do you calculate the Plastic moment?
What is the plastic moment?
M_p=[sigma_yA(y1+y2)]/2
The maximum moment that can be sustained by a beam of elastoplastic material
To find y, break the cross-sectional area into two and y is the distance from the centroid of the divided face to the actual centroid
What is the difference between the stress and strain transformation equations?
The shear strain (gamma) takes the place of Tau except it is gamma/2. Epsilon takes the place of sigma normally
What is the Strain energy equation for linear deflection and angular deflection?
- U=P*d/2
2. U=M*Theta/2
What are the two variations of the Modified Castigliano’s Theorem?
- d_i=int((M/EI)*(dM/dP) dx)
2. theta_i=int((M/EI)*(dM/dM_0) dx)
What is the equation for the required section modulus of a beam under bending?
S=M_max/Sigma_allow
S=I/c where c is the maximum distance away
What is the theoretical limit for the section modulus under bending?
S=0.5Ah
A is the total area of both flanges
h is the distance between the center of the two flanges
What is an example of the superiority of a closed-section rectangular beam over an I beam?
Increase torsional resistance
How do you calculate Iyz?
Summation of Adydz
For each block
Where dy and dx are the distance from the individual block centroids to the complete centroid