Torsion-loaded rod-shaped component with different fibre reinforcements for tensile and compressive loading
AssigneesThyssenkrupp Federn Und Stabilisatoren GmbH, thyssenkrupp AG
InventorsJörn Kiele, Werner Hufenbach, Martin Lepper, Jens Werner
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Abstract
A torsion spring may be configured as a torsion bar or a helical spring made of a spring wire made of fiber-composite material. The torsion spring may have a plurality of layers of fiber reinforcement that have been saturated with a matrix material, wherein the layers may have fibers that are tension-loaded and fibers that are compression-loaded. The at least one compression-loaded group may have a lower group stiffness than the tension-loaded group with the highest group stiffness. Methods for designing or making torsion springs made of fiber-composite material are also disclosed.
Claims24
A torsion spring comprised of a spring wire made of fiber-composite material and including a plurality of layers of fiber reinforcement that have been saturated with a matrix material, wherein each of the plurality of layers includes only fibers that are tension-loaded or only fibers that are compression-loaded, wherein the plurality of layers comprise tension-loaded groups of layers and compression-loaded groups of layers, wherein at least one compression-loaded group of layers has a lower group stiffness than a tension-loaded group of layers with a highest group stiffness.
A method of making a torsion spring made of a multiple-ply fiber-composite material, the method comprising:
- pre-designing the spring;
- forming groups of fibers made of layers in contact with one another and having an identical loading direction;
- determining computationally a group stiffness for each group of fibers;
- adjusting the group stiffnesses of compression-loaded groups such that the compression-loaded groups have a lower group stiffness than a tension-loaded group with a highest group stiffness;
- forming pairs from an inside towards an outside so that each pair comprises a tension-loaded group and a compression-loaded group that are radially adjacent;
- determining a group ratio as a quotient calculated as a relationship between the group extensional stiffness values of the tension-loaded group and the compression-loaded group of each pair;
- minimizing shear stresses between adjacent groups via variation of the stiffness ratios by at least one of varying a layer wall thickness, varying a type of material, or varying a fiber angle until the group ratio is in a range from 0.2 to 5;
- and
- repeating all steps except for pre-designing the spring until a desired loadbearing capability has been achieved with a given spring stiffness profile.
Dependencies are inferred from the claim text.