Issue 36

T. Fekete, Frattura ed Integrità Strutturale, 36 (2016) 78-98; DOI: 10.3221/IGF-ESIS.36.09

‘Loads/environmental conditions’, ‘Flaws’ and ‘Material properties’. (Note: the term hyper- will be omitted thereafter, so hyper-nodes will be referred to as nodes; also, the inside nodes of a node will be denoted sub-nodes.) The sub-node ‘Loading’ of the node ‘Loads/environmental conditions’ represents data resulting from ‘Thermal-hydraulic assessments’, while the sub-node ‘Env. Cond.’ (=environmental conditions) represents the data produced by ‘Neutron-transport calculations’. The arrow connecting ‘Loading’ and ‘Env. Cond.’ signifies the fact that there is some relation between the two domains, not further specified here (e.g. both of them have influence on the ageing behavior of structural materials). At the ‘Flaws’ node, the two sub-nodes represent the size of the flaws and their geometrical distribution both modeled during calculations and also detected in the wall of the equipment respectively. The arrow connecting the two sub-nodes depicts that there exists a relation between the postulated and the detected flaw-size. The nature of the relation is not further discussed here, as the detailed specification is the task of a given project. The outer node labeled ‘Qualification of test methods’ represents the fact that the qualification of the test method is an essential requirement. The ‘Material properties’ node represents material data sets (e.g. thermo-mechanics and strength parameters, fracture mechanics parameters, parameters that describe plastic behavior, etc.) that are necessary for completing Structural Mechanics calculations. The two sub-nodes of the node signify that there are material parameters used during calculations and also derived from material tests respectively. The arrow connecting the two sub-nodes depicts the fact that there exists a relation between the material parameters used during simulations and those evaluated from the tests. The detailed specification of the relation and its discussion is a task of a given, special project. The outer node labeled ‘Qualification of test methods’ represents the fact that the qualification of the test method is an essential requirement.

Figure 8 : The PTS Structural Mechanics Analyses methodology as the refinement of the Conceptual Model of Structural Integrity.

The edge labeled ‘Ageing’ represents the aspect that material properties that are valid in aged conditions of the materials must be used in calculations, as they have a large impact on the results; while the edge labeled ‘Crack propagation’ depicts the aspects that: (1) crack propagation prior to the PTS event needs to be taken into account at the initial conditions of calculations, (2) one of the goals of a given calculation is to elaborate the relations between loads and propagation

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