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Strain energy driven deployable structures have recently become of high interest to the deployable space structures community. Made out of thin composite sections, these structures possess increased stiffness and stabilization while reducing payload masses significantly. The added capability of self-deploying provides additional benefit in reducing structural complexity due to traditional mechanical systems typically required to deploy. One challenge to using such a structure is the high deployment accelerations that could potentially cause damage to the onboard payload if not managed properly. A solution to damp these deployments, while not sacrificing the performance benefits gained, is highly sought after within the aerospace community. The research presented herein suggests a method of passively damping deployments through means of tailoring the matrix constituent of composite materials typically used in fabrication of these strain energy deployed structural members. An optimal composite laminate for such members is described to include discrete elastic and viscoelastic plies. It has been identified that a pure shear stress state induced in the viscoelastic plies of typical cylindrical members (tape springs, slit tubes, etc.) when subjected to high shear strains. The intention is to key on this respective viscoelastic lamina and tailor it in a way that provides a sufficient amount of structural damping while still preserving the deployment torque required for successful deployment. These factors lead to the design of a custom combined loading Picture Frame Shear (PFS) fixture to test plain weave composite lamina in high shear strain load cases similar to operational conditions. Before viscoelastic characterization can occur, the PFS fixture was tested using current plain weave materials of interest. Various load cases including variable displacement rates, variations in matrix constituents and early viscoelastic stress relaxation behavior were observed. Another

The structural changes are characterized by the development of deformation or microshear bands in coarse-grain interiors, followed by homogeneous evolution of new grains at high strains. The mechanism of fine grain production and the factors controlling grain refinement during hot multidirectional deformation are discussed in detail, Belgorod State University

This thesis discusses the investigation of graphene/ hexagonal Boron Nitride (hBN)heterostructures grown by Sergei V. Novikov and Tin S. Cheng using molecular beam epitaxy (MBE), with a focus on measurements recorded using atomic force microscopy (AFM), in particular conductive AFM (CAFM). MBE is a relatively uncommon deposition technique for graphene growth that offers a route to scaleable high quality material. In this thesis three different carbon sources have been used to grow strained graphene samples at high temperature (up to ~ 1700 degC) on exfoliated hBN flakes. These samples have been subsequently analysed using a range of techniques including AFM, CAFM, lateral force microscopy (LFM), Raman spectroscopy, and angle resolved photoemission spectroscopy (ARPES). A particular focus is placed on the recorded strain of these structures, measured with the aid of the hexagonal graphene/hBN moiré superlattice pattern formed at the interface of the stacked 2D structure. In order to carry out the CAFM measurements shown, electrical contacting procedures have been developed as part of this work in order to measure electrically isolated graphene/ hBN regions. The most prominent of these methods has been the deposition of a conductive silver nanowire networking layer. During AFM contact mode scanning the appearance of a graphene/ hBN moiré pattern deformation that follows the tip scan direction was observed and has been investigated. Large differences between trace (forward scan) and retrace (backwards scan) imaging have been seen in the resulting moiré pattern. These differences have been explained by considering the strong tip-surface interaction between the probe and the graphene surface, along with the large locally applied pressure exerted by the tip that increases the graphene/ hBN van derWaals interaction. Using an electron beam carbon source for MBE graphene growth, a high level of precision has been achieved that has allowed for narrow graphene bands with unifo