Functionality
* The new name of the 'LIRA-SAPR' software LIRA-FEM: Why?

Seismic analysis of structures

In the LIRA-FEM (LIRA-SAPR) software, it is possible to carry out the seismic analysis by the following methods:

  • Spectral method with modal analysis;
  • Direct integration of the equations of motion (Time History Analysis);
  • Nonlinear static method (Pushover Analysis).

Spectral method

Example. Mode shapes
Example. Mode shapes

Earthquake analysis of buildings and structures is quite often performed by the spectral method that involves decomposition of motion into mode shapes. In LIRA-FEM program, the response spectrum method may be applied for seismic analysis. In this method, at the first stage, the eigenvalues of mode shapes are determined. Then for each mode shape, the inertial earthquake forces are determined. Then they will be considered as static loads.

Analysis parameters

Analysis parameters

To define analysis parameters by the spectral method, follow these steps:

  1. to create a load case of an "Earthquake" type. (Note: the type of load case depends on the selected building code);
  2. to select the load name (building code or load type);
  3. to set the normative parameters of the load;
  4. to collect masses from the static load cases.

List of building codes supported in the program

  • DBN B.1.1-12:2014 (Ukraine)
  • DBN B.2.2-24:2009 (Ukraine)
  • DBN B.1.1-12:2006 (Ukraine)
  • DBN B.1.1-12:2006, Appendix B with account of nonuniform vibrations of soil (Ukraine)
  • DBN B.1.1-12:2006, Appendix G with account of torsion (Ukraine)
  • SP RK EN 1998-1:2004/2012, NTP RK 08-01.1-2017 (Kazakhstan)
  • SP RK 2.03-30-2017 (Kazakhstan)
  • SNIP RK 2.03-30-2006 (Kazakhstan)
  • EN 1998-1:2004 (EU)
  • TBEC-2018 (Turkey)
  • AzDTN 2.3-1 2010 г. (Azerbaijan)
  • PN 01.01-09 (Georgia)
  • NF P 06-013 (France)
  • IBC-2006/ASCE 7-05 (USA)
  • CHPA II-6.02-2006 (Armenia)
  • KMK 2.01.03-96 (Uzbekistan)
  • MKS 22-07-2007 (Tajikistan)
  • SNIP KP 20-02:2009 (Kyrgyzstan)
  • SN KR 20-02:2018 (Kyrgyzstan)
  • SNT 2.01.08-99* (Turkmenistan)
  • RPA 99 / version 2003 (Algeria)
  • SNIP II-7-81* (USSR)
  • SNIP II-7-81* with modif. 01.01.1996 (USSR)
  • SNIP II-7-81* with modif. 01.01.2000 with account of torsion (USSR)
  • SP 14.13330.2014/2018 (RF)
  • SP 14.13330.2018 with modif. No.1 (RF)
  • MGSN 4.19-05 (RF, Moscow)
  • SNIP II-7-81* with modif. 01.01.2000 / SP 14.13330.2011 (RF)
  • NP 031-01 for nuclear plants (RF)
Generation of accelerograms
Generation of accelerograms

In the LIRA-FEM program, for spectral analysis, it is possible to set parameters that do not depend on building codes. The ReSpectrum system is mentioned to generate the response spectrum of a single-mass oscillator from dynamic loads defined by accelerograms, seismograms, velocigrams and three-component accelerograms, as well as for mutual transformation of these loads.

Time History Analysis

Динамика во времени

Time History Analysis

In the Time History Analysis system, it is possible to analyse the dynamic load on structures with nonlinear deformations, such as structures with one-way springs and physically nonlinear systems. It is also possible to consider the G-µ dependence as a Prandtl diagram.

In the Time History Analysis system, it is easy to perform computer simulations of the behaviour of a nonlinearly deformed structure under dynamic load in time.

Pushover Analysis

Dialog box for setting the earthquake load for Pushover Analysis

Dialog box for setting the earthquake load for Pushover Analysis

The Pushover analysis algorithm (nonlinear dynamic analysis) implemented in the LIRA-FEM program is universal and may be applied to analyse various response spectrums. It takes into account the dependencies between "dynamic factor I and vibration period T", that are defined according to the building codes of different countries, such as Russia (SNIP, SP), Ukraine (DBN), Georgia, Armenia, and Central Asian countries. Moreover, the algorithm takes into account the relationship between "acceleration Sa and displacement Sd" defined in the building codes of Kazakhstan, European countries (Eurocode), and the USA (IBC-2006, ASCE 7-05). It is also possible to define a custom response spectrum and generate a response spectrum based on the user-defined accelerograms.

stk

Time History Analysis

The modelling of the dynamic loading process on the basis of accelerograms, with the calculation of forces and displacements at certain time intervals, account for the influence of damping structures and material damping.

stk

Linear solver

Static analysis, finite element library, complete dynamic analysis, floor (nodal) response spectrum, earthquake, wind pulsation, super-elements. It is available in all standard bundle configurations of LIRA-FEM.

stk

Nonlinear solver

Engineering nonlinearity, physical nonlinearity, structural nonlinearity, geometric nonlinearity, pushover analysis.

LIRA-FEM. Price list
Victor Gubchenko. New features and options for dynamic analysis in LIRA-SAPR 2022 (link in Russian)
Alexander Bryantsev. Earthquake analysis of a building according to SP RK 2.03-30-2017 in LIRA-FEM (link in Russian)
Victor Gubchenko. New features and options for dynamic analysis in LIRA-SAPR 2021 (link in Russian)
Victor Gubchenko. Modelling of seismic isolating and damping devices in LIRA-FEM

Project made by LIRA-FEM users

Multifunctional complex Alliance Palace

Multifunctional complex Alliance Palace

As part of the structural system "overground structure - foundation - soil," the bearing capability of the 41-storey "Alliance Palace" building in Batumi is verified for design and critical earthquake loads.

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