Composite Booms Research Articles

Computational and experimental study on dynamic instability of extended bistable carbon/epoxy booms subjected to bending

Bistable reeled composite booms (BRCs) constructed from braided carbon/epoxy plies are suitable candidates for use as extendible booms or as elements of large deployable space structures. However, without modification, BRCs have an open section which limits their torsional stiffness, and makes them prone to collapse under low bending moments. In this study a “roll-up” deployable photovoltaic (PV) solar array with two side-by-side extendible BRCs is used as a case study to analyse the dynamic behaviour of BRCs on spacecraft undergoing rotational manoeuvres numerically. The BRCs have rotational accelerations applied to their roots to simulate the effect of being attached to a manoeuvring spacecraft. Budiansky-Hutchinson criterion is used to define an instability failure point based on a change in cross-sectional shape. This was used to estimate the maximum angular acceleration. While it is extremely difficult to replicate the behaviour of a large flexible lightweight structure in microgravity on the ground, an experiment to determine the point of collapse of BRCs under gravity were used to verify the simulation results.

Viscoelastic effect on unfolding behaviors of shape memory composite booms

The viscoelastic time dependent unfolding behavior including structural nonlinearity of thin-walled shape memory composite booms are experimentally and numerically investigated. The shape memory composites are fabricated with woven fabric fibers and a resin of shape memory polymers (SMPs). The numerical model based on the elastic properties of the woven fabric fiber considering its actual fabric geometry and the shape memory and viscoelastic properties of the SMP resin is developed. A thin-walled cylindrical boom, which can be flexibly folded to an arbitrary configuration and be autonomous deployable, is fabricated using shape memory composites. While the boom is unfolding at elevated temperature, the shape memory, and the viscoelastic behaviors are investigated for their application in self-deployable structures.

Application of System-Identification Techniquest to Health Monitoring of On-Orbit Satellite Boom Structures

The integration of composites into spacecraft is challenged by the risk of damage initiation andpropagation during storage, launch, and service life. Elastically deployable composite booms are being developed for space utility.Matrix cracks are considered a primary form of damage caused by packaging before launch. However, while on orbit, most damages are induced by the environmental effects on the polymers. A well-developed structural health monitoring system will provide information for the dynamic control of the satellite and the condition of the deployable mechanisms on the space vehicle. A structural health monitoring methodology, based on the system-identification techniques, is proposed to identify the structural degradation in laminated composite booms. Nondestructive evaluation techniques, frequency-response analysis and autoregressive with exogenous input models are used to approximate the transfer functions between input and output sensing signals. Structural degradation is identified by examining the change of transfer functions at different storage states. A single-input/single-output approach is adopted in this paper. The proposed methodology is validated through experimentation in which matrix cracking is gradually induced by packaging the sample.

Completely stripped solar sail concept using bi-stable reeled composite booms

The Surrey Space Centre is currently working on CubeSail, a 5×5 m 2 nano-solar sail spacecraft to be fitted inside a 3U Cubesat platform. The CubeSail mission has a two-fold aim: first, to demonstrate the concept of solar sailing using a 3-axis stabilized sail and second, to demonstrate the potential use of its large membrane as a drag augmentation device for de-orbiting satellites and launch vehicles' upper stages in low Earth orbit (LEO). The novel solar sail concept presented here is a result of the highly restrictive area-to-mass ratio and volume constraints imposed by the mission requirements. Therefore, this concept can be readily scaled up to produce future very high performance sailcrafts. Research on ultra-lightweight deployable structures leads to the invention of a new bi-stable composite boom that entails a light and simple deployment subsystem. This simplicity is the key feature that enables the sail to be attached along the length of the booms, thus reducing the structural mass requirement of these support structures. In the completely stripped sail concept the previously considered square or quadrant membrane is split into a set of parallel strips, in order to achieve a uniaxial tension state in the film. Also, a test-bed created for the successful deployment under gravity conditions of the 5 m 2 prototype sail is presented.

Vibration Control of Composite Spacecraft Booms Subjected to Solar Heating

In this paper, piezoelectric feedback control of vibration and instability of spacecraft booms modeled as circular thin-walled cross-section beams and subjected to solar radiant heating is investigated. Having in view that composite material systems are likely to play a great role in the design of these devices, the beam constituent materials encompass non-classical effects such as anisotropy and transverse shear. In addition, in order to induce beneficial elastic couplings, a special ply-angle distribution achieved via the usual helically wounding fiber-reinforced technology, the so called filament winding, is implemented. The dynamic governing equations including the temperature effects and the related boundary conditions are obtained via the application of Hamilton's principle. Toward the end of controlling the oscillations and prevent the occurrence of the thermal dynamic instability, a feedback control capability based on the use of the piezoelectric induced strain actuation is implemented. The performance of its implementation considered in conjunction with that of the structural tailoring are highlighted and pertinent conclusions are derived.

Dynamic Response Control of Rotating Composite Booms Under Solar Radiation

This paper deals with the thermally induced dynamic response analysis of a composite blade rotating at a constant speed. Fiber-reinforced composite thin-walled beam are used in a variety of aerospace applications, including helicopter rotor blades, tilt rotor aircraft, turbine engines, compressor blades, only to name a few. The composite beam is modeled as a tapered thin-walled beam which is subjected to a temperature field. A number of non-classical features such as transverse shear, secondary warping, anisotropy of constituent materials, and rotary inertias have been included in the model. The structure of the blade consists of a host graphite epoxy laminate with spanwise distributed transversely isotropic (PZT-4) sensors and actuators. The discussed results reveal that the thermal environment has a detrimental effect on the blade dynamic response. The active controller is implemented via the combined displacement and velocity feedback control methodology, which can alleviate the deleterious effect associated with the thermally induced dynamic response.