Vol.3, No 13, 2003 pp. 497-510
UDC 539.219 665.941
FRACTURE MECHANICS OF RUBBER
E.E. Gdoutos1, I.M. Daniel2,
P. Schubel2
1School of Engineering, Democritus
University of Thrace, GR-671 00 Xanthi, Greece
2Northwestern University, Evanston,
IL 60208, USA
The fundamental principles of the application of fracture mechanics to
rubber are briefly discussed. The importance of the problem arises because
of the large nonlinear deformation of rubber which introduces difficulties
in the solution of the boundary value problem of a cracked body made of
rubber. The tear behavior of rubber can be conveniently described by the
critical tearing energy which is a characteristic property of the material.
The results of an experimental study of determining the crack growth behavior
and critical tearing energies of pure tire rubber are presented. Constrained
tension and trousers specimens were used for mode-I and mode-III loading,
respectively. In the trousers specimens the force necessary to grow the
crack varies widely from a maximum value at crack initiation to a minimum
value at crack arrest. This result to a stick-slip stable crack propagation,
that is, the crack arrest and reinitiates of fairly regular intervals.
In the constrained tension tests crack initiation triggers catastrophic
growth. Results for the critical tearing energies for mode-I and mode-III
are given.
MEHANIKA LOMA GUME
Osnovni principi primene mehanike loma na gumu ukratko su razmotreni. Značaj
problema se javlja usled velike nelinearne deformacije gume, što dovodi
do poteškoća u rešavanju problema granične vrednosti naprslog tela od gume.
Ponašanje pri kidanju gume može se na podesan način opisati preko kritične
energije kidanja koja je karakteristično svojstvo materijala. Prikazani
su rezultati eksperimentalne studije na odredjivanju ponašanja u napredovanju
prsline i kritičnih energija kidanja čiste gume. Ograničeno istezanje i
opitni uzorak sa kracima su svaki ponaosob korišćeni za opterećenje u modu
I i modu III. Kod opitnog uzorka sa kracima, sila koja je neophodna za
proširenje prsline široko varira od maksimalne vrednosti pri početku stvaranja
prsline, do minimalne vrednosti pri zaustuvljanju prsline. To vodi stick-slip
(prijanjajuće-klizećem) stabilnom napredovanju prsline, to jest, zaustavljanju
prsline, i ponovnim počecima po prilično pravilnim intervalima. U testovima
ograničenog istezanja, zapodinjanje prsline pokreće katastrofično napredovanje.
Rezultati za kritične energije kidanja za mod I i mod III su dati.
