General

General

POLYFLOW: Transient viscoelastic calculation may fail at early steps because of lack of precision

    • FAQFAQ
      Participant

      Transient viscoelastic calculation may fail at early steps because of lack of precision, the most typical symptom being reduction of the time step below the minimum value assigned. Why is that? When running a transient viscoelastic calculation, the viscoelastic stresses often start from zero and usually grow exponentially. This is especially true in a situation involving extension or compression. This may hinder the evaluation of the precision especially at the beginning of the calculation where stress values are small but show a rather fast growth. It is therefore important to make sure that the viscoelastic stresses are not considered for the evaluation of the precision. If the keyword PRECISIONSTRESS is included in a .p3rc file for the POLYDATA session, then the viscoelastic stresses will be considered for precision evaluation. By default, viscoelastic stresses are discarded from this evaluation.