CODECHECK: Checks (Strength + Service Limit State)

Perform all required checks in the Strength Limit State and Service Limit State according to AASHTO LRFD

This includes the checks due to bending, shear and torsion, as well as interaction due to shear + torsion and the check against brittle failure in the Strength Limit State, and the stress limitation checks and the check for the limitation of the crack widths in the Service Limit State, and further the fatigue check.

The checks are performed based on the given envelopes for the elements assigned by assemblies and the respective results are stored under the given result name.

The possibly already existing amounts of reinforcement are considered (greater values from user-defined and evaluated reinforcement).

Note: The user-defined amounts of reinforcement can be defined in the respective property sets in the cross section definition. The stress checks and the crack check can only be performed, if the exposure zones for determining the respective exposure conditions or factors are defined within the cross section definition.

Parameters

Day (day)

Day in the construction phases at which the check should be performed

Result name (resname)

Result name; user-defined name under which the various results of the checks should be stored

Fatigue Combinations and Groups

Fatigue I (env3)

Name of the envelope/combination/combination group which should be taken for the fatigue check

Type of check

Flexure (flexure)

Option to perform the check due to bending (moment and normal force)

Brittle failure (brittle)

Option to perform the design against brittle failure

Shear (shear)

Option to perform the check due to shear (as well as the design of the joints in composite structures, particularly between concrete surfaces of different age)

Torsion (torsion)

Option to perform the check due to torsion

Interaction (interact)

Option to perform the check due to interaction of shear + torsion

Fatigue (fatigue)

Option to perform the check due to fatigue

Stress limitation

Option for performing the checks for stress limitation

Crack control (crack)

Option to perform the design in regard to the limitation of crack widths

Detailing (detailing)

Option to apply detailing rules for reinforcement

Strength Limit State Combinations and Groups

Strength I-V (env)

Name of the envelope/combination/combination group for which the check in the Strength Limit State should be performed

Service Limit State Combinations and Groups

Service I (env1)

Name of the envelope/combination/combination group which should be taken as Service Limit State combination I for the respective checks

Service III (env2)

Name of the envelope/combination/combination group which should be taken as Service Limit State combination III for the respective checks

The evaluated results can be addressed by their result names in the result presentation (tab Design Checks in the Result Data in Results).

Calculation assumptions for the checks in the Strength Limit State

• Non-linear material behavior (stress-strain diagrams according to the standard)
• Tensile stresses in the concrete are not considered.
• The strain of bonded reinforcement is equal to the strain of the surrounding concrete.
• Transformed cross sections are considered: Net cross section (i.e. minus duct areas) until the grouting of the ducts, i.e. until the task TENSION or the calculation task GROUT is performed. The stiffness of the steel area of the tendons is considered after performing these tasks. The stiffness of the reinforcing steel is considered after the concrete has hardened, i.e. after the task CONCRETE or the calculation task HARDEN.
• The ultimate limit state occurs if any ultimate strain in the concrete, prestressing steel or reinforcing steel is reached.

Calculation assumptions for the checks in the Service Limit State

• Linear-elastic behavior of all materials except concrete under tension
• The concrete is assumed to be cracked, if the tensile stress exceeds the tensile strength fr. In this case the tensile strength of the concrete is neglected.
• Transformed cross sections are considered (see above).