Orthotropic modulus ratio

For orthotropic materials, such as fabric and roving-reinforced constmction, E and Et are the elastic moduli in the longitudinal (L) and transverse (T) directions, Glt is the shearing modulus associated with these directions, vlt is Poisson s ratio giving the transverse strain caused by a stress in the longitudinal direction, and Vtl is Poisson s ratio giving the longitudinal strain caused by a stress in the transverse direction. The modulus... 

An element will have hoth geometric and material properties. Spatially, an element is defined by its nodes however, additional geometric input is usually required for line and surface elements. For structural analysis the minimum material property is the modulus of elasticity. In most cases, Poisson s ratio or shear modulus must also be specified. If an orthotropic material is used then the orientation of the material must be specified as well as the elastic constants relative to each principal axis. If post-yield behavior is to be modelled then an elasto-plastic material model must be applied and the yield and hardening behavior defined. Constitutive adhesive and sealant models are discussed in more detail in O Chap. 23. Additional material properties will also be required for dynamic or thermal analysis. 

It is apparent from Equations 8.42 and 8.43 that four material elastic properties (compliance or stiffness) are needed to characterize the in-plane behavior of a linear elastic orthotropic lamina. It is convenient to define these material properties in terms of measured engineering constants (Young s moduli, El > d Ej, shear modulus Glt, and Poisson s ratios u,lt and (Xtl). The longitudinal Young s... 

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