Changguo Wang

VIBRATION CHARACTERISTICS SIMULATION OF WRINKLED CIRCULAR ANNULUS-SHAPED GOSSAMER SPACE STRUCTURE

Ultra-lightweight Gossamer space structures have received the wide attention due to their small packaging volume and low launching cost. Since wrinkles are a common deformation state and the main failure mode of such structures and vibration behaviors are the major factor of the structural design and control, a better understanding of the wrinkling characteristics and the vibration behaviors of the wrinkled membrane structure is thus very essential and desirable. In this paper, a modal analysis method incorporating the wrinkling analysis is presented to simulate the vibration characteristics of a wrinkled membrane structure. The effects of the wrinkles on the structural vibration behaviors are also summarized in detail in the end.

Influence Parameter Analysis and Wrinkling Control of Space Membrane Structures

This paper aims to find the effective wrinkling control strategy for space membrane structures, including square solar sails and inflatable reflectors. The wrinkles in a square solar sail were first predicted using a nonlinear finite element solution. Analysis of wrinkling influence parameters was then evaluated to determine the shape and wrinkling control schemes for the solar sail. The wrinkling criterion and characteristics were then determined by introducing the principal stress criterion and an elliptical assumption for the shape of the wrinkled region in inflatable reflector. We then evaluated the effects of the parameters on the wrinkling characteristics. These results were used to determine an effective wrinkling control strategy. The wrinkling control for the solar sail effectively improved the membrane stiffness and controlled the initial prestress in the membrane, while simultaneously reducing the structural scale. For the inflatable reflector, controlling edge tension using a tape as a tension-compliant border was an effective wrinkling elimination scheme, and this was verified by the numerical results in the end. The conclusions of this paper are useful when applied to wrinkling and shape control of space membrane structures.

Wrinkling Behaviors of Gossamer Structure with Stretched Annulus-Shape under In-Plane Torsion

In this paper, an out-of-plane wrinkling function is constructed and then is introduced to the buckling theory to complete the wrinkling analysis. Two key techniques (initial imperfection and prestress) are then introduced to the shell model to perform the post-wrinkling numerical analysis of the annulus-shaped membrane under in-plane torsion. The numerical analysis is also performed to evaluate the effects of the thickness and structural scale on the wrinkling behaviors. The results indicate that the wrinkling behavior is intensely affected by structural size compared with membrane thickness. Results from analytical models and simulations agree well, and show both are effective to predict detailed wrinkling behavior of gossamer structures accurately.

Wrinkling Analysis Method Based on Singular Displacement Component Modification for Membrane Structure

KT = tangential stiffness matrix KTcr = critical tangential stiffness matrix K T = modified critical tangential stiffness matrix u = true solution of the original equation u = modified displacement solution u = wrinkling mode u = tangential displacement increment = imperfection scaling = modified parameter o = higher-order infinitesimal = first-order characteristic vector cr = critical wrinkling mode