COBEM99

S9 Fenômenos Não-Lineares e Caóticos em Engenharia

Title:

INTERACTION DIAGRAMS FOR PIPING COMPONENTS SUBJECTED TO CYCLIC THERMAL LOADING

Summary :

THIS WORK PROPOSES A METHOD TO THE CONSTRUCTION OF INTERACTION DIAGRAMS TO BE USED IN THE ANALYSIS OF THE INELASTIC BEHAVIOR OF PIPING COMPONENTS SUBJECTED TO CYCLIC THERMO-MECHANICAL LOADING. THIS LOADING IS COMPOSED BY THE SIMULTANEOUS APPLICATION OF AN INTERNAL PRESSURE AND A LONGITUDINAL TEMPERATURE GRADIENT. THE INTERACTION DIAGRAMS ARE VERY USEFUL AS DESIGN TOOLS, SINCE THEY PRESENT THE EXPECTED BEHAVIOR OF THE COMPONENT SUBJECTED TO A CERTAIN LOADING HISTORY, AS A FUNCTION OF THE PRESSURE AND THERMAL STRESS CALCULATED ON A PURELY ELASTIC BASIS. THE METHOD PRESENTED TO THE CONSTRUCTION OF THESE DIAGRAMS MAKES USE OF FINITE ELEMENT MODELS BUILT ON THE ANSYS PROGRAM, AND INCLUDES THE CALCULATION OF THE ELASTO-PLASTIC AND CREEP MATERIAL PROPERTIES. THIS METHOD WAS APPLIED TO A TYPICAL SITUATION OF A LONG THICK-WALLED TUBE, MADE OF INCOLOY 800H, AND SUBJECTED TO A CONSTANT INTERNAL PRESSURE AND CYCLIC THERMAL GRADIENT CAUSED BY A LINEAR VARIATION OF TEMPERATURE ALONG A PART OF ITS LENGTH. THE INTERACTION DIAGRAM CORRESPONDING TO THE RATCHETTING BEHAVIOR FOR THIS PROBLEM WAS GENERATED.

Author :

Alves, José Luis Drummond
de Vilhena, Carlos José Carneiro
Landau, Luiz 0

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