There are a number of other good practice activities that are suggested to be performed. This is particulatly important as the level of sophisitication of analysis and models increase, and as our capability to intuitively (using engineering judgement) check model results diminishes. Before initial results are available, make estimates of what type of behaviour expect Modelling sequence should be: Linear elastic, model components first then slowly complete the model: soil only, (self weight in all directions, static loads, point, self-weight, eigen analysis, etc.); dynamic loads (point loads, etc.); free field ground motions (see chapter 4 and 5) components of structural only (for example containment only, internal structure only. Aux building, and in general all structures on the nuclear island (EPR has 9 separate sub-structures), start with a fixed base model for all, etc.), and then full structural model (just the structure, no soil), static loads (self weight in three directions to verify model and load paths, point loads to verify model and load paths); then dynamic loads (point loads, and seismic loads) (Visual verification of results!!!, visual verification of element shapes complete structure and foundation, (apply same load scenarios as above) complete structure, foundation, soil system, (apply same load scenarios as above) Equivalent linear modeling, and observe changes in response, to determine possible plastification effects. It is very important to note that it is an elastic analysis, with reduced (equivalent) linear stiffness. Reduction in secant stiffness really steams from plastification, although plastification is not explicitly modeled, hence an idea can be obtained of possible effects of reduction of stiffness.
There are a number of other good practice activities that are suggested to be performed. This is particulatly important as the level of sophisitication of analysis and models increase, and as our capability to intuitively (using engineering judgement) check model results diminishes. Before initial results are available, make estimates of what type of behaviour expect Modelling sequence should be: Linear elastic, model components first then slowly complete the model: soil only, (self weight in all directions, static loads, point, self-weight, eigen analysis, etc.); dynamic loads (point loads, etc.); free field ground motions (see chapter 4 and 5) components of structural only (for example containment only, internal structure only. Aux building, and in general all structures on the nuclear island (EPR has 9 separate sub-structures), start with a fixed base model for all, etc.), and then full structural model (just the structure, no soil), static loads (self weight in three directions to verify model and load paths, point loads to verify model and load paths); then dynamic loads (point loads, and seismic loads) (Visual verification of results!!!, visual verification of element shapes complete structure and foundation, (apply same load scenarios as above) complete structure, foundation, soil system, (apply same load scenarios as above) Equivalent linear modeling, and observe changes in response, to determine possible plastification effects. It is very important to note that it is an elastic analysis, with reduced (equivalent) linear stiffness. Reduction in secant stiffness really steams from plastification, although plastification is not explicitly modeled, hence an idea can be obtained of possible effects of reduction of stiffness.
CHAPTER_7_Nov_16_2016_BJ_edits_1_19pm.docx