Universal Pushover Analysis
LIRA-FEM program implements Universal Pushover Analysis for multi-mass design model.
Seismic analysis of structures
LIRA-FEM is mentioned for seismic analysis of structures. The software package implements different method for earthquake analysis.
- Finite element analysis
- Static analysis
- Dynamic analysis
- Nonlinear analysis
- Seismic analysis
- Design combinations
- Frame analysis
- Beam analysis
Seismic analysis of structures
In the LIRA-FEM 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
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
To define analysis parameters by the spectral method, follow these steps:
- to create a load case of an "Earthquake" type. (Note: the type of load case depends on the selected building code);
- to select the load name (building code or load type);
- to set the normative parameters of the load;
- 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)
- СНРА 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
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
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
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.
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.
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.
Nonlinear solver
Engineering nonlinearity, physical nonlinearity, structural nonlinearity, geometric nonlinearity, pushover analysis.
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
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.
Evaluate the software
If you have any doubt, download the Demo version and evaluate the program or contact our Support Team for more details.