Question
What is the difference between primary and secondary loads of Creep and Shrinkage which are created during construction stage analysis?
Answer
When performing construction stage analysis, the program automatically generates load cases. If time-dependent material properties are defined to consider the effects of creep and shrinkage of concrete, loads for creep and shrinkage are also generated, and they are classified into primary and secondary loads.
Creep and shrinkage are phenomena that cause deformation rather than physical loads. To implement these effects in analysis, the process of converting deformations into loads results in primary forces. Additionally, if the structure is statically indeterminate, secondary stresses arise that constrain creep and shrinkage, resulting in secondary forces.
In other words, the Primary Force is a virtual force that causes deformation, while the Secondary Force is the force generated in the structure due to Creep and Shrinkage deformations.
Therefore, the results obtained from the Primary Force, which is a virtual force, except for Deformation, are not used in practical applications, and it is not appropriate to use them in the review of analysis results.