An Analytical Shape Memory Polymer Composite Beam Model for Space Applications

2016 ◽  
Vol 16 (02) ◽  
pp. 1450093 ◽  
Author(s):  
D. Bergman ◽  
B. Yang
Keyword(s):  
Shape Memory ◽  
Polymer Composite ◽  
Geometric Model ◽  
Shape Memory Polymer ◽  
Constitutive Law ◽  
Finite Difference Approximation ◽  
Dynamic Equations ◽  
Difference Approximation ◽  
Beam Model ◽  
Space Applications

Shape memory polymer composite (SMPC) structures, due to their ability to be formed into a small compact volume and then transform back to their original shape, are considered as a solution in the design of light-weight large deployable space structures. There is a wide array of constitutive and qualitative work being done on SMPC’s but little or no development of dynamic equations. This paper documents a macroscopic model for the shape fixation and shape recovery processes of a SMPC cantilever beam. In particular the focus is on the shape fixation process, whereby a quasi-static equilibrium model can be used instead of a full equation of motion. Numerical results are obtained in this regard by use of finite difference approximation with Newton’s method. This formulation combines a nonlinear geometric model with a temperature dependent constitutive law. Additionally, the dynamic equations of the SMPC cantilever are derived. Future work will include a dynamic numerical model, and a finite element model of the SMPC structure.

Deployment performance of shape memory polymer composite hinges at low temperature

2019 ◽  
Vol 30 (17) ◽  
pp. 2625-2638 ◽  
Author(s):  
Van Luong Le ◽  
Vinh Tung Le ◽  
Nam Seo Goo
Keyword(s):  
Low Temperature ◽  
Shape Memory ◽  
Polymer Composite ◽  
Room Temperature ◽  
Shape Memory Polymer ◽  
Heating Element ◽  
Heating Process ◽  
Space Applications ◽  
Design Modification ◽  
The Impact

Shape memory polymer composite hinges, adapted for possible space applications, were successfully designed and fabricated, and performance tests at room temperature confirmed their full recoverability in our previous studies. Since shape memory polymer composite hinges are intended for space applications, they should be able to operate at low temperature. Even though the deployment of the hinge at room temperature triggered by the stimulation of a heating element has been quite promising, a suitable design for a shape memory polymer composite hinge with a heating element is more important at low temperatures because shape memory polymer composite hinges lose much heat to the environment. The recoverability of shape memory polymer composite hinges and the impact of the heating element design on the deployment time at low temperature are brought to light in this article. A shape memory polymer composite hinge with an attached heating element was fabricated as in our previous studies. The necessary power and supply power for deployment of the shape memory polymer composite hinge at a low temperature of –10°C were calculated, and a finite element analysis for the heating process was performed with the supply power. A folding and deployment test of the shape memory polymer composite hinge at –10°C was performed to show its shape recoverability. However, the shape memory polymer composite hinge did not deploy to its original shape. To determine the reason, measurements of temperature distribution were done using an infrared camera and thermocouples. The results revealed that the low temperature along the two side edges of the shape memory polymer composite tape prevented full deployment of the shape memory polymer composite hinge, which also revealed the need for design modification. The folding and deployment test of our modified shape memory polymer composite hinge demonstrated a nearly full deployment.

Blocking force measurement of shape memory polymer composite hinges for space deployable structures

2018 ◽  
Vol 29 (18) ◽  
pp. 3667-3678 ◽  
Author(s):  
Thanh Duc Dao ◽  
Nam Seo Goo ◽  
Woong Ryeol Yu
Keyword(s):  
Shape Memory ◽  
Polymer Composite ◽  
Mechanical Performance ◽  
Force Measurement ◽  
Shape Change ◽  
Shape Memory Polymer ◽  
Mass System ◽  
Manufacturing Method ◽  
Moment Arms ◽  
Repeated Test

This study introduces a method for measuring the blocking force of a shape memory polymer composite hinge to quantify the performance of a shape memory polymer composite hinge for space deployable structure applications. A detailed design of how to select heating elements for a self-deployable configuration is also suggested. The shape memory polymer composite hinge consists of two reverse carpenter shape memory polymer composite tapes that were made from carbon-epoxy fabric, shape memory polymer resin, and two heating elements. The heating elements were attached to the shape memory polymer composite tape using the composite manufacturing method, and they were used as the heating source in the deployment test. The blocking force and moment of the hinge were measured using a pulley–mass system setup to examine the mechanical performance of the hinge. During the test, the shape change was recorded with a camera to calculate the moment arms. While the blocking force was 7.21 N in the initial test, it decreased slightly with the working cycle and was 6.27 N in the repeated test. The maximum hinge moment was 0.47 N m in the repeated test. In addition, the results revealed that a pop-up phenomenon occurred at the middle period of deployment. These results confirm that the shape memory polymer composite hinge works well with heating elements and provide a guideline for performance evaluation of the shape memory polymer composite hinge.

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