Stochastic Finite Element and Satellite Structure Design - Finite Element Analysis for Satellite Structures - page 244

Fig. 5.3 Base plate modeled as 3D beam elements with B.Cs [ 11 ]

Table 5.2 Sensitivity index of performance function with respect to design space parameters

Variable Sensitivity index

Real-constant set-1 t y 0.117683

Real-constant set-1 tz 0.110029

Real-constant set-2 t y 0.012153

Real-constant set-2 tz 0.017118

Modulus of Elasticity -0.0000001

Material yield stress 0.000005

Load set-1 0.002447

Load set-1 0.000341

Load set-1 -0.000092

Load set-1 -0.003401

A set of material properties and acceleration load are defined as: modulus of
elasticity mean, modulus of elasticity covariance, material yield stress (r y ), r y
covariance, material density mean, material density covariance, thermal expansion
mean, thermal expansion covariance, modulus of elasticity distribution type, r y
distribution type, density distribution type, thermal expansion distribution type.

- Material_Properties(1,1:12) = [72e6 0.06 150e3 0.11 2.63e-6 0 23e-6 01111].

Simulations results are shown in Tables 5.2 and 5.3 . The critical value of
probability of failure is 0.5, so the satellite structure has safe design. The ratio
of the calculated probability of failure to the its critical value proves that the factor
of safety used during the deterministic FE analysis can be reduced.