Thin-Shell Deployable Reflectors with Collapsible Stiffeners Part 1: Approach
نویسندگان
چکیده
Thin-shell deployable reflector structures that are folded elastically in a nearly inextensional mode have been recently realized, exploiting the recent availability of high-modulus, ultrathin composite materials. An inherent and significant limitation of this approach is that these structures remain “floppy” in their deployed configuration. This paper presents a general concept for increasing the deployed stiffness of such structures, through the addition of a collapsible edge stiffener around the rimof a reflector dish.Ananalytical expression of the frequency/stiffness related to the softest deformation mode of a thin-shell reflector structure is presented, both with and without the stiffener. During folding, the stiffener collapses elastically, and this behavior is facilitated by the introduction of suitable discontinuities within the stiffener, or between the dish and the stiffener. A detailed study of a range of different options is presented, and one particular scheme is selected and optimized. For a specific example, a stiffness increase by a factor of 31 and a fundamental frequency increase by a factor of 4 are achieved, with a mass increase of only
منابع مشابه
Thin-Shell Deployable Reflectors with Collapsible Stiffeners: Experiments and Simulations
This paper presents an experimental and computational study of four deployable reflectors with collapsible edge stiffeners, to verify the differences in behavior that had been predicted in a previous theoretical study. The experimental models have different geometric configurations and are made of two different plastics. Both folding experiments and vibration tests in the fully deployed configu...
متن کاملThin-Shell Deployable Reflectors with Collapsible Stiffeners: Part I – Approach
Thin-shell deployable reflector structures that are folded elastically in a nearly-inextensional mode have been recently realized, exploiting the recent availability of high-modulus, ultra-thin composite materials. An inherent, and significant limitation of this approach is that these structures remain “floppy” in their deployed configuration. This paper presents a general concept for increasin...
متن کاملUltra Thin Deployable Reflector Antennas
We have recently proposed a new concept for deployable reflectors consisting of a thin parabolic carbon-fibre-reinforced-plastic (CFRP) shell stiffened along the edge by an elastically collapsible stiffener. Here we show that a stiffener accounting for less than 10% of the total mass of the reflector increases the stiffness of the softest deformation mode of the deployed reflector by 48 times, ...
متن کاملBuckling of Stiffened Thin-Walled Cylindrical Shells under Axial Compression with Symmetrical Imperfections
This study aimed to investigate the effects of stiffeners on buckling of thin cylindrical shells under uniform axial compression. To this end, more than 300 finite element models of stiffened cylindrical shells were prepared. The variables considered are shell thickness, number, dimension and the location of the vertical and horizontal stiffeners as well as circular symmetrical imperfections. R...
متن کاملDeployable Membrane Reflectors
This paper is concerned with the design of a new type of multi-purpose deployable membrane reflector. The reflector structure consists of a central expandable hub, a number of thin-walled foldable ribs connected radially to the hub, and a precision-shaped membrane supported and tensioned by the ribs. This concept is known as a collapsible rib-tensioned surface reflector. A methodology for the d...
متن کامل