scholarly journals Experimental and Numerical Study of Smart Polymeric Composite Beam Embedded with Ni-Ti Shape Memory Alloy

Author(s):  
Samir Ali Amin ◽  
Ali Yasser Hassan
1996 ◽  
Vol 459 ◽  
Author(s):  
J.-E. Bidaux ◽  
J.-A. E. Månson ◽  
R. Gotthardt

ABSTRACTThe use of shape-memory-alloy (SMA) fibres to actively changethe stiffness of a composite beam is investigated on a model system composed of an epoxy matrix with a series of embedded pre-strained NiTi fibres. Stiffness changes are detected through shifts in the natural vibration frequency of the beam. When electrically heated, the pre-strained NiTi fibres undergo a phase transformation. Since the shape recovery associated with the transformation is restrained by the constraints of both the matrix and the clamping device, a force is generated. This force leads to an increase in the natural vibration frequency of the composite beam. Depending on the degree of fibre pre-strain, either ordinary martensite, R-phase or a mixture of the two can be stress-induced. It is found that the R-phase gives rise to the largest change in vibration frequency for a given temperature increase and the most reversible behaviour. Its low transformation strain is also more favourable for fibre-matrix adhesion. The effect of stress relaxation in the polymer matrix on the composite response is discussed.


2017 ◽  
Vol 52 (8) ◽  
pp. 1089-1101 ◽  
Author(s):  
SMR Khalili ◽  
A Saeedi

The response of laminated hybrid composite beam with embedded shape memory alloy wires subjected to impact of multiple masses is analytically investigated. Two degree of freedom spring-mass system and Fourier series are used in order to study the low velocity impact phenomenon on the resulting hybrid composite beam. A linearized contact law is chosen to calculate the contact force history. The effect of pseudo elasticity of wires as well as the recovery stresses generated in shape memory alloy wires due to shape memory effect is investigated. The beam is subjected to impactors with various masses, radii, and initial velocities. Impacts are occurred on the top and/or bottom surface of the beam. The effects of volume fraction of shape memory alloy wires, location of embedded wires, location of impacts and pre-strain in shape memory alloy wires on the contact force history and the deflection curve of the beam are investigated. The obtained results illustrated that embedding shape memory alloy wires in the laminated composite beam caused the deflection of the beam to occur more local at the points of impact, in comparison with the beams without shape memory alloy wires. Moreover, embedding 0.2 volume fraction of the shape memory alloy wires reduced the maximum deflection of the beam subjected to impact of 2 impactor masses by 57% and 3 impactor masses (on both sides) by 12%. Pre-straining the wires caused more reduction in deflection of the beam under impact loading.


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