|For calculation of the main characteristics of shock absorber, user has to enter the following structure properties: the radius r0 of the horizontal rigid element, where the force is applied; the radius r1 of toroidal (fitting) part of thin shell of revolution; the angle α0, where this part of structure is connected smoothly to the conical (cylindrical) shell; thickness of the shell h, which is constant in both directions; the stiffness of the vertical spring C, and material properties. It is assumed that the material of the shell is orthotropic with the elastic stress-strain relationship:|
User has to enter modulus of elasticity E1 and E2 of the material in meridional and circumferentional directions, as well as smaller Poisson’s ratio
ν21. We assume that E2≥E1. This case corresponds to the structure reinforced mostly in the circumferential direction. The second Poisson’s ratio is calculated using formula (2). We check also the restriction (3) before the calculation.
Please use the same system of units throughout the calculation. For instance, if you use force unit N and length unit m, the units of spring stiffness and modulus of elasticity should be N/m and N/m2 respectively. Obviously, the result of calculation will have the same unit system in this case: deflection – m, load – N, stresses – N/m2, energy – Nm.
The program calculates the characteristics of shock absorber in the following range of deflection amplitude 0<w0≤6r1. To design the effective shock absorber, the stiffness of the shell structure and the spring should be of the same order. Approximately we have in this case