The pre-stressing or post-stressing process suffers from tensional losses due to a variety of factors, which can be immediate or long-term. CivilFEM model both kinds of losses, allowing very precise pre-stressed concrete calculations by implementing losses due to steel relaxation, thermal effects, anchor slippage, friction, concrete creep, and other known effects that can be taken into consideration in the CivilFEM pre-stressing tools.
Concrete properties change during its lifespan. The user can define the evolution of these properties and check the model at different time periods to optimize the construction process and ensure the proper long-term stability and behavior of the structure.
Apart from the non-linear constitutive law models included in CivilFEM, a material can be defined using different material behavior laws such as Drucker-Prager, Mohr-Coulomb (C&Phi variables), Cam-Clay, Hyperbolic model (Duncan-Chang) & Hoek and Brown. That suit certain materials better than the default material models. Orthotropic and anisotropic materials can be defined too, for those cases where materials with different properties in different directions are used. In addition “Initial stress state” can be analyzed.
CivilFEM includes the option for considering creep and shrinkage effects of concrete. These factors affect a concrete structure in the long run, and can lead to unexpected and unwanted results after a long time. With this CivilFEM capability, the analysis will be more accurate in cases where these factors play a major role, such as concrete wall, bridges, dams or membrane structures.
CivilFEM includes advanced material models to accurately represent non-linear yielding behavior such as concrete material model, isotropic stress-strain diagram and Drucker Prager as well as a multi-linear elastic behavior. The stress-strain diagrams are defined by means of the analysis diagram which includes the non-linear concrete behavior by code.
For every defined material, the user can change its constitutive law from the default linear stress-strain diagram to a non-linear one. These are defined either by code (concrete, reinforcing steel and structural steel) or stress strain diagram definition (generic material).On the other hand, these material laws may have non-linear elastic behavior or yield conditions (isotropic stress-strain and concrete material model).
CivilFEM can handle concrete and other low tension material. The user crack data option assists in predicting crack initiation and in simulating tension softening, plastic yielding and crushing. This option can be used for concrete or any other user material.
Fiber-reinforced concrete with steel or microsynthetic fibers and low or high fiber addition rates.
Buckling problems are usually analyzed using a linear approach but it often falls under unsafe conditions. In order to obtain better and safer results, CivilFEM can perform a second order buckling analysis using the large displacement and non-linear material behavior method for any type of elements that takes into consideration the change in geometry and stiffness during the non-linear buckling process.
Construction stage and time-dependent engineering problems form a key part in understanding the response of a structure and the subsequent behavior during the construction process period. CivilFEM enables this kind of analysis by implementing time-dependent properties, activation and deactivation of elements, and graphical representation tools, providing the user with intermediate results that will prove very useful for the understanding of the construction non-linear behavior and effects.