Editorial Type:
Article Category: Research Article
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Online Publication Date: 01 Sept 2010

Fatigue Investigation of Elastomeric Structures

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Page Range: 194 – 212
DOI: 10.2346/1.3481658
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Abstract

Fatigue crack growth can occur in elastomeric structures whenever cyclic loading is applied. In order to design robust products, sensitivity to fatigue crack growth must be investigated and minimized. The task has two basic components: (1) to define the material behavior through measurements showing how the crack growth rate depends on conditions that drive the crack, and (2) to compute the conditions experienced by the crack. Important features relevant to the analysis of structures include time-dependent aspects of rubber’s stress-strain behavior (as recently demonstrated via the dwell period effect observed by Harbour et al.), and strain induced crystallization. For the numerical representation, classical fracture mechanical concepts are reviewed and the novel material force approach is introduced. With the material force approach at hand, even dissipative effects of elastomeric materials can be investigated. These complex properties of fatigue crack behavior are illustrated in the context of tire durability simulations as an important field of application.

Copyright: The Tire Society
FIG. 1
FIG. 1

Characteristic distribution of energy release rate along circumferential length at belt edge (tire size: 385/65 R22.5).


FIG. 2
FIG. 2

U-shaped crack at belt edge.


FIG. 3
FIG. 3

Schematic Paris-Plot.


FIG. 4
FIG. 4

Applied strain, stress, and crack growth histories of a PS specimen (filled NR).


FIG. 5
FIG. 5

Energy release rate (filled NR).


FIG. 6
FIG. 6

Paris-Plot (filled NR).


FIG. 7
FIG. 7

Distribution of energy release rate along circumferential length for two different tire designs (tire size: 385/65 R22.5).


FIG. 8
FIG. 8

Effect of SIC on fatigue crack growth rate: a) filled NR strain crystallizes, b) filled SBR does not strain crystallize.


FIG. 9
FIG. 9

TFA specimen with kinked and branched crack due to SIC.


FIG. 10
FIG. 10

Time-dependent loading for investigating the dwell-effect.


FIG. 11
FIG. 11

Numerical and experimental results showing the dwell-effect.


FIG. 12
FIG. 12

(a) Material forces induced by inhomogeneities and discontinuities; (b) material volume forces induced by inhomogeneity due to inelasticity; (c) resulting crack driving force due to crack.


FIG. 13
FIG. 13

Material nodal forces along the circumferential length (size: 385/65 R22.5).


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