Table of Contents

Stand, Method of Analysis:
FEA, Loading:
 Weight of engine = 45 lbs
 Connections that transmit the weight in the Yaxis are modeled as "bonded."
 Connections that are prone to slide or are bolted were modeled as "no separation."
FEA versus Calculations  Bolt:
Calculation Assumptions: Rockers take the weight of the engine
 No friction between clamped faces
 Use 5/16 bolt with min diameter=.260"
 Use Max Shear Stress Theory (Conservative)
 Steel Sy=36,259 psi
 Shear Tau max = (.5)*(Sy) = 18,129.5 psi
Calculations Explained:
 Friction force between rocker and side
 Ff = Mu* N
 Ff = ( .7 * 45lb) / 2
 Ff = 15.75 lb
Sum moments about point 0.
 (200 inlb) +2 * (F * 7") + (15.75 * 6") = 0
 F = 7.5 lbs
Max Shear Stress
 Tau = (4 * F) / (Pi * (dia)^2)
 Tau =(4 * 7.5) / (Pi * (.260)^2)
 Tau = 141.3 psi
Factor of Safety
 FOS = Sy / (2 * Tau)
 FOS = 36,259 / (2 * 141.3)
 FOS =128
Calculation Results:
 Shear Stress of bolt= 141.3 psi
 Factor of safety = 128
Fea Results:
 Shear Stress of bolt= 278.57 psi
 Max stress = 2440.3 psi in side
 Factor of safety = 15 (Ansys max)
FEA versus Calculations  Base:
Assumptions: Weight of engine is supported by 2 sides
 Bolts are in complete tension
 Weight of engine = 45 lb
 Use 1/4"20 bolt with min diameter=.1876"
Sum moments about point 0:
 (200 inlb) F1*(5.45") + F2* (5")= 0
 200=5.45(F1) + 5(F2)
 200= 5.45 (F1) + 5 * ( 22.5 +F1)
 200=5.45(F1) + 112.5 +5(F1)
 87.5=10.45(F1)
 F1= 8.37 lb
 F1/ (2 sides)= 4.2 lbs
Sum forces in Y axis:
 F1 + F2 22.5lbs = 0
 F2=22.5 + F1
 F2= 30.87
 F2 / (2 sides) = 15.4 lbs
Max tensile stress at F2:
 Tau= 4* (F Bolt) / (Pi*(dia)^2)
 Tau=(4*15.435) / (Pi*(.1876)^2)
 Tensile stress= 558.4 psi
Calculation Results:
 Tensile stress= 558.4 psi
Fea Results:
 Tensile stress = 461.4 psi
FEA Deformation:
Max deformation occurs at 30 degree tilt and is equal to .0001 inches.
FEA Stress at Tilt
Titled away from dyno 30 degrees, shear stress of bolt equal to 1074.4 psi.