ij] is the reduced stiffness constant of a unidirectional.
The reduced stiffness constant of a unidirectional layer, off its material directions is obtained by:
Divide the reaction forces found in step "b" at the L/3 and 2L/3 points by the corresponding deflections found in step "a" in order to determine the stiffness constant ([k.
Determine the stiffness constant for the unsupported rail plus the stretcher and brace system.
Second, all stiffness constants
are determined separately, and requirements from a thermodynamic point of view, such as objectivity are not incorporated when simply applying the anisotropic stiffnesses as finite strain tangent stiffness.
2] plane respectively, and the method yields elastic stiffness constants (12) [C.
Elastic constants of the die-drawn products measured by the ultrasonic method are tabulated (Table 3), both as stiffness constants [C.
The measured pattern of anisotropy agrees well with that calculated for a uniaxially oriented sheet, based on taking the mean of averaging the stiffness constants
and the compliance constants respectively obtained for the predicted orthorhombic elastic constants.
However, a detailed mapping of mechanical anisotropy and the computation of stiffness constants are quite involved and require a nonlinear least-square fit of the data to the predictions of a model for wave propagation.
Finally, still another concern addressed in this paper is the robustness of the algorithm to recover the stiffness constants from the time-of-flight data (6, 10).
The first aim of the present work is to fill the void in data by measuring the five independent stiffness constants [C.
The five independent stiffness constants of extruded LCP were determined by the contact method previously described .