Stresses in a flat plate due to a loose pin pressing against a cracked hole

1997 ◽  
Vol 32 (2) ◽  
pp. 145-156 ◽  
Author(s):  
S Lin ◽  
D A Hills ◽  
D Nowell
Keyword(s):  
Stress Intensity ◽  
Elastic Limit ◽  
Closed Form Solution ◽  
Form Solution ◽  
Elastic Contact ◽  
Intensity Factors ◽  
Distributed Dislocation ◽  
Elastic Design ◽  
Radial Cracks ◽  
Cracked Hole

The elastic contact stress field caused by a radially loaded pin in a nearly conforming hole is studied. The elastic limit of the configuration is found, together with crack tip stress intensity factors for radial cracks emanating from the bolt hole, the latter using the distributed dislocation approach. A closed-form solution is therefore generated to enable an elastic design philosophy to be followed for both perfect and flawed configurations, providing that there are no nearby boundaries.

scholarly journals Stress Intensity Factors for Layered Pressure Vessel Inner Layer Through Cracks

2019 ◽  
Author(s):  
Joel R. Hobbs
Keyword(s):  
Elastic Modulus ◽  
Stress Intensity ◽  
Closed Form ◽  
Stress Intensity Factors ◽  
Pressure Vessel ◽  
Closed Form Solution ◽  
Pressure Vessels ◽  
Form Solution ◽  
Intensity Factors ◽  
Friction Forces

Abstract A difficulty encountered when performing Fitness-for-Service assessments for layered pressure vessels (LPVs) is the lack of stress intensity factor solution in literature that produce accurate results for inner layer longitudinal through cracks. Using surrogate solutions such as a through crack in a plate or cylinder produce results that can be overly conservative especially for longer cracks. This is largely due to the ability of a layered pressure vessel to redistribute hoop load to other layers, the restricted radial movement of the cracked layer, and the friction forces applied in the cracked region. To understand this problem, a parametric finite element model (FEM) generator was developed that is capable of producing layered pressure vessel models with inner layer through cracks. The results from the FEMs were used to create a dataset of inner layer through crack stress intensity factors (Ki) for layered pressure vessels corresponding to variations of internal pressure, radius, layer thicknesses, friction factor, and crack length. The elastic modulus of the material also has an effect on Ki but, for this dataset, the elastic modulus was fixed at the typical value for steel – 29,500 ksi (203 GPa). Finally, a non-dimensional model was developed and calibrated using the dataset. This allows Ki to be calculated without the need of a FEM using a closed-form equation. The results of the closed-form solution were then compared to FEM results showing accuracy was generally within 10%.

Transmission of Rapidly Applied Loads Through Articular Cartilage Part 2: Cracked Cartilage

1996 ◽  
Vol 210 (1) ◽  
pp. 39-49 ◽  
Author(s):  
P A Kelly ◽  
J J O'Connor
Keyword(s):  
Articular Cartilage ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Articular Surface ◽  
Mode Ii ◽  
Intensity Factors ◽  
Distributed Dislocation ◽  
Mode Of Failure ◽  
Elastic Fracture ◽  
Dislocation Technique

A model of articular cartilage suffering rapidly applied loads and containing splits and fissures is presented. The possibility of cracks propagating through the cartilage collagen network is analysed using elastic fracture mechanics. Cracks are modelled using the distributed dislocation technique and the crack tip stress intensity factors are thereby evaluated. The mode I (tensile) stress intensity factors are generally much larger than the mode II (shearing) factors for cracks at the articular surface and close to, and at oblique angles to, the cartilage-bone interface, two regions where cartilage cracks have been observed. This suggests an opening, tensile mode of failure. The mode II factors are larger for cracks running along the interface. The rapidly loaded cracked cartilage model may explain the splits observed in osteoarthrotic cartilage.

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