Finite element analysis of solar sail force model with mission application

Abstract

A finite element approach is used to calculate the components of forces and moments acting on a square solar sail at a sun-sail distance equal to one astronomical unit. The model takes into account the deformation effect induced by the solar radiation pressure, where the incidence of the reflected photons changes as a function of the local orientation of the sail surface. Assuming a specular reflection model, the analysis shows that the maximum value of the transversal thrust component takes place when the solar zenith angle is about 36°, which is in accordance with the result available for a classical flat solar sail. Notably, the modulus of the moment due to the solar radiation pressure takes its maximum value approximately at the same (solar zenith) angle.

Effects of attitude constraints on solar sail optimal interplanetary trajectories

“…In a preliminary and simplified mission analysis, a flat sail and an ideal force model [3] may be assumed, so that the solar sail is approximated as a rigid mirror that specularly reflects all the incident light. A succeeding and more refined analysis, which includes the real thermo-optical characteristics of the reflective film material [21], or the sail billowing [28,29,30], represents a straightforward problem. The spacecraft propulsive acceleration vector a is written as [21]…”

Thermal-structural analysis of a square solar sail

“…The model relevant to the stress analysis, described in Refs. [11,12], uses elements with pure displacement degrees of freedom: S4 (four-node full integration shell element) for the sail membrane, B31 (two-node beam element) for the supporting boom, and T3D2 (2-node truss element) for the cables. The T3D2 element has been provided with "no-compression" behaviour, which makes the cables free of sagging, thus allowing a possible loss of pre-tensioning of the solar sail to be detected.…”

“…6, is about 22% greater than that calculated in Refs. [11,12] since the sail surface is larger due to the uniform heating, and the pre-tensioning field is less effective. This means, if the solar rays impinge on the sail reference surface at a right angle, the only remarkable effect of the thermal loads results from the uniform part of the field temperature.…”

“…In fact, when the angle of incidence increases, for each of the considered values of the clock angle (δ = {0, 45, 90} deg), the initial value of the maximum sail deflection is about 25% greater than that predicted in Refs. [11,12] by a pure stress analysis. By going on with the iterative procedure, the thermal gradients produce, at the free edges of the solar sail, remarkable out-of-plane deformations.…”

“…[11] has been improved in Ref. [12], where the resultant forces acting on the spacecraft are calculated by taking into account the local curvature of each sail element in the evaluation of the solar pressure.…”