Adjustable CTE graphite-epoxy bar
AssigneeThe Perkin-Elmer Corporation
InventorMichael K. Krim
Life of this patent
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Abstract
A structural element and method of fabricating a structural element having a zero expansion in a given direction. A bar member having left and right hand sections of positive and negative coefficients of thermal expansion is tuned so that expansion of one section is exactly offset by contraction of the other section in a varying temperature environments.
Claims13
A structural element having a specific overall expansivity along a given axis, comprising in combination;
- a member comprising first and second sections integrally formed therewith,
- said member comprising a plurality of layers of graphite epoxy composite,
- each of said sections having a length and coefficient of thermal expansion such that overall expansion or contraction is zero and wherein,
- the layers in said first section have different wrap angles from the layers in said second section.
A method for fabricating a structural element comprising the steps of
- forming a member having a first section with a negative coefficient of thermal expansion and a second section having a positive coefficient of thermal expansion,
- measuring the coefficient of thermal expansion of portions of said first and second sections,
- calculating the necessary length of one of said sections to give a desired expansivity for a given length of the member,
- cutting off a portion of said one of said sections to shorten it to the required length,
- cutting off a portion of the other of said sections to cause said member to conform to said given length.
A truss, comprising in combination,
- a plurality of struts
- each of said struts composed of first and second sections having a length and coefficient of thermal expansion such that overall expansion or contraction of the strut due to temperature variations is zero,
- first and second rings,
- each of said struts having an end fixed to each of said rings,
- each of said first and second rings connected to alternate ends of said first and second sections of said struts.
A structural element having a specific overall expansivity along a given axis, comprising in combination;
- a member comprising first and second sections integrally formed therewith,
- said member comprising a plurality of layers of graphite epoxy composite,
- each of said sections having a length and coefficient of thermal expansion such that overall expansion on contraction has a predetermined value wherein the number of layers in said first and second sections are different.
Dependencies are inferred from the claim text.