THE EFFECTS OF FATIGUE ARE THE DECAY OF MECHANICAL CHARACTERISTICS AND STRENGTH UNDER CYCLIC LOAD WHICH DEPEND PRIMARILY ON THE AMPLITUDE AND NUMBER OF CYCLES. The broad research subject and importance of structural behaviour under the three aspects of safety, durability, and service life, guided the investigation along the three standard methods of experimental research, theoretical speculation and application to typical cases. The long and laborious experimental research consisted in a repeated series of each of the following: -compression tests, on prismatic specimens, using constant load cycles having a maximum range of intensity equal to 1/3 of strength, up to 12 million cycles (Ch. 2); -indirect Brazilian tensile tests, on cylindrical specimens, using constant load cycles having a maximun range of intensity equal to 1/2 of strength, up to 3 million cycles (Ch. 3); -steel-concrete bonding test, with bond slip experiments for up to 2,5 million cycles (Ch. 4); -permeability tests on concrete specimens subjected to fatigue levels due to compression ranging between 0 and 6 or 12 illion of cycles (Ch. 6); -fracture tests on prismatic specimens subjected to fatigue due to compression ranging between 0-6 or 12 million of cycles (Ch. 7); -identification and comparison of static monotonic load tests on sample specimens; -typical cases: the first concerns the design of a railway bridge, the second concerns the study of railway sleepers subject to the action of train axles; -the phenomena of dynamic interaction of mobile load-structures in order to determine the number of load cycles of decreasing amplitude during a vehicle's transit and subsequently calculating the number of equivalent cycles of constant amplitude which may be compared with lab tests; in this manner, it is possible to carry out a fetigue check, concerning a given service life, by comparing cyclic actions with the response experimental laws.
FATICA E DECADIMENTO DEI MATERIALI E DELLE STRUTTURE SOTTOPOSTE AD AZIONI CICLICHE. Coordinatori: Prof. Ing. Remo Calzona Prof. Ing. Ezio Dolara / Dolara, Ezio; R., Calzona. - STAMPA. - 1:(1996), pp. 1-613.
FATICA E DECADIMENTO DEI MATERIALI E DELLE STRUTTURE SOTTOPOSTE AD AZIONI CICLICHE. Coordinatori: Prof. Ing. Remo Calzona Prof. Ing. Ezio Dolara
DOLARA, Ezio;
1996
Abstract
THE EFFECTS OF FATIGUE ARE THE DECAY OF MECHANICAL CHARACTERISTICS AND STRENGTH UNDER CYCLIC LOAD WHICH DEPEND PRIMARILY ON THE AMPLITUDE AND NUMBER OF CYCLES. The broad research subject and importance of structural behaviour under the three aspects of safety, durability, and service life, guided the investigation along the three standard methods of experimental research, theoretical speculation and application to typical cases. The long and laborious experimental research consisted in a repeated series of each of the following: -compression tests, on prismatic specimens, using constant load cycles having a maximum range of intensity equal to 1/3 of strength, up to 12 million cycles (Ch. 2); -indirect Brazilian tensile tests, on cylindrical specimens, using constant load cycles having a maximun range of intensity equal to 1/2 of strength, up to 3 million cycles (Ch. 3); -steel-concrete bonding test, with bond slip experiments for up to 2,5 million cycles (Ch. 4); -permeability tests on concrete specimens subjected to fatigue levels due to compression ranging between 0 and 6 or 12 illion of cycles (Ch. 6); -fracture tests on prismatic specimens subjected to fatigue due to compression ranging between 0-6 or 12 million of cycles (Ch. 7); -identification and comparison of static monotonic load tests on sample specimens; -typical cases: the first concerns the design of a railway bridge, the second concerns the study of railway sleepers subject to the action of train axles; -the phenomena of dynamic interaction of mobile load-structures in order to determine the number of load cycles of decreasing amplitude during a vehicle's transit and subsequently calculating the number of equivalent cycles of constant amplitude which may be compared with lab tests; in this manner, it is possible to carry out a fetigue check, concerning a given service life, by comparing cyclic actions with the response experimental laws.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
