S3  Ciências dos Materiais    Titulo: LOW - CYCLE FATIGUE. CYCLIC PROPERTIES OF AN AL 6061-T651   Resumo : ABSTRACT: THE USE OF LINEAR ELASTIC FRACTURE MECHANICS FOR FATIGUE LIFE PREDICTION PURPOSES, ASSUMES THAT CRACK LIKE DEFECTS ARE PRESENT IN THE STRUCTURE COMPONENT UNDER EVALUATION. THE ANALYSIS IS CONDUCTED ASSUMING THAT THE DEFECT GROWS UNTIL A CRITICAL SIZE IS ATTAINED AND COLLAPSE OF THE STRUCTURE OCCURS. GENERALLY THE INITIATION PHASE IS NOT TAKEN INTO CONSIDERATION, UNDERESTIMATING THE REAL FATIGUE LIFE. THE ERROR CAN BE CONSIDERABLE IN THE THE CASE OF LONG LIFES WHERE THE INITIATION PHASE CAN REPRESENT UP TO 80% OF THE TOTAL FATIGUE LIFE. OF THE CURRENT METHODS USED TO PREDICT THE INITIATION PHASE THE LOCAL APPROACH METHOD IS THE MOST IMPORTANT . ITS APPLICATION, HOWEVER, SUPPOSES THAT CYCLIC PROPERTIES OF THE MATERIAL ARE KNOWN. IN THE PRESENT PAPER THE RESULTS OF AN EXPERIMENTAL PROGRAM DESIGNED TO OBTAIN THE CYCLIC PROPERTIES OF AN AL 6061-T651 ARE PRESENTED. KEY-WORDS: FATIGUE, INITIATION, PROPAGATION, LOW- CYCLE FATIGUE.     Autores : Costa, José Domingos Fernandes, António Augusto Ribeiro, Alfredo Silva     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local