User defined RSA curve

The RSA Spectrum curve in the Seismic Wizard can now be defined by a set of data points, in addition to the existing fully automated code generated option and manual entry of code spectral curve change points. This new feature is introduced in Tekla Structural Designer 2019i for the US Headcode. Further information on Tekla Structural Designer can be found here: https://www.tekla.com/products/tekla-structural-designer