1Slenderness Ratio
$SR=\frac{L_e}{k}$
effective length / radius of gyration
2Radius of Gyration
$k=\sqrt{\frac{I}{A}}
4Normal Stress
$S=\frac{F}{A}
5Factor of Safety
$FS=\frac{S_{ultimate}}{S_{design}}
6Normal Stress w/ D and d
$S=\frac{F}{\frac{π}{4}(D^2-d^2)}
7Thickness
$t=\frac{D-d}{2}$
$t=r_o-r_i
8Shear Stress
$S=\frac{F}{πDt}
9Bolt Stress
$S_{bolt}=\frac{\frac{PA_{cylinder}}{N_{bolts}}}{A_{bolt}}
11Modulus of Elasticity of Steel
$E_{steel}=30x10^6 psi
12Modulus of Elasticity of Aluminum$
$E_{Al}=\frac{1}{3}E_{steel}
13Modulus of Rigidity of Steel
$G=12x10^6psi
14Poissons Ratio and 2big
$v=-\frac{Ɛ_{lateral}}{Ɛ_{longitudinal}}$
$E=2(v+1)G
15Axial Deformation
$δ=\frac{FL}{AE}
16Elongation
$Ɛ=\frac{δ}{L}
17Deformation Due to Own Weight
$δ=\frac{ρgL^2}{2E}
18Dilatation
$e=Ɛ_x+Ɛ_y+Ɛ_z$
$e=\frac{F}{AE}(1-2v)
19Thermal Elongation and Thermal Stress
$δ=αL∆T$
$S=Eα∆T$
$\alpha=6.51x10^{-6}°
20Bending/Flexural Stress
$S_b=\frac{Mc}{I_x}
21Flexural/Bending Stress Square Cantilever Beam
$S_b=\frac{6M}{bh²}
22Flexural/Bending Stress Circular Cantilever
$S_b=\frac{32M}{πD³}
24Maximum Moment 2 formulas
$M_{max}=\frac{ωL^2}{8}$
$M_{max}=\frac{PL}{4}
25Band Saw
$S=\frac{Et}{D}
26Slenderness Ratio
$SR=\frac{L_e}{k}
27Effective Length and End Coefficient
$L_e=KL$
$C=\frac{1}{K^2}

28Max Moment
$M_{max}=\frac{PL}{4}$
$M_{max}=\frac{\omega L^2}{8}
29Moment of Inertia Square
$I_x=\frac{bh^3}{12}
30Moment of Inertia Triangle
$I_x=\frac{bh^3}{36}
31Moment of Inertia Circle
$I_x=\frac{\pi r^4}{4}$
$I_x=\frac{\pi D^4}{64}
32Radius of Gyration
$k=\sqrt{\frac{I}{A}}
33Buckling Formula: Euler's
$F_c=\frac{π^2EI}{L_e^2}
34Buckling Formula: JB Johnson
$F_c=S_yA\left[1-\frac{S_y(L_e/k)^2}{4π^2E}\right]
35Maximum Shear Stress (Combined Stresses)
$Ss_{max}=\sqrt{\left(\frac{S_x-S_y}{2}\right)^2+S_s^2}
36Maximum Stress (Combined)
$S_{max}=\frac{S_x+S_y}{2}+Ss_{max}
37Minimum Stress (Combined)
$S_{min}=\frac{S_x+S_y}{2}-Ss_{max}
38Degree of Freedom
$DOF=3(N-1)-2L_{pair}-H_{pair}$
$DOF=3(N-1)-2L_{pair}
39Alternating Stress
$S_a=\frac{S_x-S_y}{2}
40Mean Stress
$S_m=\frac{S_x+S_y}{2}
41For Static Failure, FS 2 formulas
$FS=\frac{S_y}{S_m}$
$FS=\frac{S_u}{S_m}
42Instantaneous Center
$v=r\omega$
$\omega=\frac{v_A}{r_A}=\frac{v_B}{r_B}