1.3.15. Post-processing tools

1.3.15.1. Laminate results

After calculation, laminate results can be analyzed layer per layer in the post-process.

FIGUREEE

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Within this window, any layer of the laminate can be selected together with one of the results available in the drop-down menu. The actual results available read as follows:

  • Max. failure index Tsai-Wu (Complete) - Failure index taken at bottom and top of the laminate

  • Security coef. Tsai-Wu (Complete) -

  • Security coef. Tsai-Wu (Simple) - Tsai-Wu security factor calculated at the mid-plane of the lamina

  • Security coef. LaRC04_m1 - Reserve factor for matrix tensile failure mode

  • Security coef. LaRC04_m2 - Reserve factor for matrix compressive failure mode

  • Security coef. LaRC04_m3 - Reserve factor for fibre tensile failure mode

  • Security coef. LaRC04_m4 - Reserve factor for fibre compressive failure mode (kink-band formation)

  • Security coef. LaRC04_m5 - Reserve factor for matrix failure under biaxial compression mode

  • Security coef. LaRC04_m6 - Reserve factor for combined matrix and fibre failure mode

  • Layer Stresses

  • Layer Strains

  • Layer Stress Top

  • Layer Stress Base

  • Layer Shear Stresses

  • Layer Shear Strains

Of the many failure criteria available, RamSeries implements the Tsai Wu. This corresponds to a first ply failure analysis for which the sequence of load application is not significant. First ply failure criteria can be used to assess the global strength of a laminate and is the most common criteria used in linear analysis. Within this context, the structural integrity is usually reported in terms of a reserve factor (RF) or margin of safety. This reserve factor can be obtained layer per layer by invoking the calculation of the ‘Security coef. Tsai-Wu (Complete)’ and/or ‘Security coef. Tsai-Wu (Simple)’ results in the post-process tool. Alternatively, a failure index (FI) can be obtained by invoking the calculation of the ‘Max. failure index Tsai-Wu (Complete)’ result. Note that a FI value larger than one indicates failure. On the contrary, failure is predicted by a RF value smaller than unity.

Alternatively, the LaRC04 (Langley Research Center) failure criteria is also implemented in RamSeries [Pinho_2005]. This is actually a set of failure criteria based on physical models for each failure mode. The corresponding security factor can be obtained by selecting the ‘Security coef. LaRC04’ result of the failure mode under analysis.