COMPDYN 2015 5 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, V. Papadopoulos, V. Plevris (eds.) Crete Island, Greece, 25–27 May 2015 FROM THE NOTIONS OF NONLINEARITY TOLERANCES TOWARDS A DEFICIENCY IN COMMERCIAL TRANSIENT ANALYSIS SOFTWARES AND ITS SOLUTION A. Soroushian 1 , P. Wriggers 2 , and J. Farjoodi 3 1 Structural Engineering Research Center, International Institute of Earthquake Engineering and Seis- mology (IIEES) S.Lavasani (Farmaniyeh), North Dibaji, West Arghavn, No. 21, Tehran 19537, Iran a.soroushian@iiees.ac.ir 2 Institute of Continuum Mechanics, University of Hannover Applestrasse 11, Hannover 30167, Germany wriggers@ikm.uni-hannoer.de 3 School of Civil Engineering, University College of Engineering, University of Tehran Enghelab Avenue, Tehran 11365 jfarjood@ut.ac.ir Keywords: Nonlinear Analysis, Static, Dynamic, Tolerance, Halt of Analysis, Accuracy. Abstract. The notions of nonlinearity tolerances in static and dynamic analyses are reviewed. A deficiency in conventional nonlinear dynamic analysis, also existing in the transient analy- sis commercial soft wares, is recognized. A simple approach to practically eliminate the defi- ciency is proposed, and its adequacy is demonstrated numerically. 1899