VERSION HISTORY
LIRA-FEM

Analysis & design of reinforced concrete (RC) structures

Reinforced concrete (RC) structures

Last updated: March 27, 2024
  • Enhanced algorithm for analysis of reinforcement with off-centre tension at small eccentricities (including by strength).

  • Analysis of reinforcement is optimized with account of fire resistance (now it is possible to avoid the significant increase in reinforcement in individual elements where the compressive or least tensile reinforcement was increased in cases of extremely small compression zones of concrete).

  • For the SP RK EN 1992-1-1:2004/2011, the condition "not less than 1.5 wall thickness" is added to the parameters for determining the min dimension of the end zone Lc of a plastic wall.

  • For plates, in the analysis for width of crack propagation by Karpenko method, the value Ψs=1 may be fixed now.

Improvements to the module for analysis & design of reinforced concrete (RC) structures

Last updated: Jan 05, 2024 16:18:09
  • For the SP RK 1992-1-1:2004/2011, in analysis of "Column" and "Pylon" element types, there may be more intermediate reinforcing items for increasing reinforcement. This option increases the analysis accuracy and makes the selection of reinforcement more efficient. The additional items are located at the edges of cross-sections. The number of such items may be specified as the input data for RC materials.

How to define the number of intermediate reinforcing items for increasing reinforcement

How to define the number of intermediate reinforcing items for increasing reinforcement

Example. Output data from analysis of reinforcement for a column with intermediate reinforcing items

Example. Output data from analysis of reinforcement for a column with intermediate reinforcing items
  • For the new reinforcement type "Wall (Bar)", the strength analysis of walls and pylons is implemented based on the linear distribution of strain in the normal section. The new reinforcement type may be assigned to bar elements of the model and bar analogues. The bearing capacity of a normal wall section is determined based on the distribution of normal stresses in the section. The relationship between the normal stresses and relative strains is based on the stress-strain diagram specified for concrete and reinforcement. The position of the reinforcement items depends on the spacing or number of reinforcement bars (rebars) along the length of the wall.

Data for analysis  of the new reinforcement type Wall (Bar)

Data for analysis of the new reinforcement type Wall (Bar)

Pattern with rebars

Pattern with rebars
  • For the type of reinforcement "Wall (Bar)", the peripheral reinforcement at the ends of walls are computed in earthquake analysis by sect. 5.4.3.4 SP RK EN 1998-1:2004/2012 "Design of structures for earthquake resistance. Part 1. General rules, seismic actions and rules for buildings". This analysis is carried out when the "Plastic Wall" mode is activated.

Restricted peripheral zones with free faces at the end of the wall (top: strain at ultimate curvature; bottom: cross-section of the wall)

Restricted peripheral zones with free faces at the end of the wall (top: strain at ultimate curvature; bottom: cross-section of the wall)

Example: earthquake analysis of a wall

Example: earthquake analysis of a wall
  • New option to compute the percentage ratio of the reinforcement area of selected/defined longitudinal reinforcement along X, Y and XY-axes (total) to the cross-sectional area of the plate.

  • It is possible to create a custom steel table with rebars; this table may be used to select required reinforcement.

How to customise the rebar list

How to customise the rebar list
  • The program is updated to support the base edition of EN 1992-1-1:2004 + A1:2014. "Eurocode 2: Design of concrete structures. Part 1-1: General rules and rules for buildings".