A boron/carbon fiber 1D laminate comprising a boron fiber layer and a carbon fiber layer having a balanced pair of carbon fiber plies embedded in a plastic resin matrix has a coefficient of thermal expansion between .+-.0.54 .mu.m/m/.degree.C. and a specific modulus greater than 8.9.times.10.sup.6 meter. A 2D boron/carbon fiber quasi-isotropic laminate having two sets of quasi-isotropic boron fiber plies, two sets of quasi-isotropic carbon fiber plies, the laminate has a Coefficient of Thermal Expansion between .+-.0.54 .mu.m/m/.degree.C. in two orthogonal directions, a specific modulus greater than 5.2.times.10.sup.6 meter in two orthogonal directions. The laminates are useful for optical mounting structures.
A uniform stiffness laminated composite shell assembly includes a plurality of composite shells. The shells are made of layers of laminates of graphite-epoxy material having fibers oriented in various stacking sequences for performing different functions in the assembly. The shells are concentrically assembled in a desired sequence with some of the adjacent ones of the shells being at least equal to or greater in axial length than others thereof and with some of the shells being adapted to perform a structural load bearing function while others of the shells being adapted to perform a load transfer function. The desired sequence of shells of the composite shell assembly provides enhanced thermal insulating properties and efficient load distributing properties for enabling use of the assembly as a tube suspension in a superconductive magnet.
A laminated composite shell assembly includes composite shells assembled together and having joint bonds connecting the assembly with an external structure and pinch rings assembled to the shells adjacent the joint bonds so as to reinforce the same. The composite shells and pinch rings are cylindrical in configuration and made of layers of graphite-epoxy material having fibers oriented in desired stacking sequences. The shells and pinch rings are concentrically assembled in a desired sequence with some of the shells being adapted to perform a structural load bearing function while others of the shells are adapted to perform a load transfer function and with the pinch rings adapted to perform additional stiffening as well as load redistributing and transfer functions in the regions of the joint bonds between the assembled shells and the external structure.
A carbon fiber hybrid laminate includes a first group of carbon fiber reinforced laminae having a positive CTE and, second group of carbon fiber reinforced laminae having a negative CTE, wherein the hybrid laminate has a tailorable in-plane CTE in the range of .+-.0.2.times.10.sup.-6 in/in/.degree. F.
A method of making a mirror structure includes assembling a supporting isogrid framework, assembling an isogrid back plane, interconnecting the supporting isogrid framework with the isogrid back plane by a truss core, and disposing an optical surface on the supporting isogrid framework.
A composite structure for use in a coordinate measuring machine (CMM) includes a metallic material joined to a non-metallic material, wherein each material possesses a coefficient of thermal expansion (CTE) less than or equal to 6.1.times.10.sup.-6 cm/cm/.degree. C. The metallic material may be INVAR, an alloy of iron and nickel, and the non-metallic material may be carbon fiber reinforced composite. Also, the metallic material may be in the shape of a space frame with the non-metallic material in the shape of stiffeners adhered to the space frame. The modulus of elasticity of the combined space frame and stiffeners is preferably greater than 140 GPa. The space frame may be a modified I-beam with reinforcing structures and mass-reducing cutouts. The stiffener may be a square tube, wherein one stiffener is adhered to each I-beam flange of the space frame. The stiffeners are ground and lapped to produce bearing tracks of high precision for air bearings to traverse. Additionally, a method for fabricating a CMM includes the steps of assembling and/or fabricating the materials and structures described above.