Experimental and Numerical Investigation into Fatigue and Fracture Assessment of Structures in the Challenging Environments of Deep Oceans

2021 ◽  
Author(s):  
Mohammad (Sasan) Iranpour
Keyword(s):  
Numerical Investigation ◽  
Fatigue And Fracture ◽  
Fracture Assessment

Design Guidelines for Doubler Plate Repairs of Ship Structures

2005 ◽  
Author(s):  
Pradeep K. Sensharma ◽  
Malcolm Willis ◽  
Aaron Dinovitzer ◽  
Nat Nappi
Keyword(s):  
Engineering Design ◽  
Low Cost ◽  
Design Guidelines ◽  
Performance Data ◽  
Ship Structures ◽  
Buckling Strength ◽  
Relative Ease ◽  
Fatigue And Fracture ◽  
Fracture Assessment ◽  
Design Guidance

The use of doubler plates or ‘doublers’ has become routine for temporary ship repairs. It is the preferred method for ships’ structural repairs for plate corrosion due to its relative ease and low cost of installation over the more costly permanent welded plate insert repair. A lack of performance data and engineering design guidance are the reasons that repairs with doublers are currently considered only temporary. This objective of this study was to develop a set of guidelines for designing and applying doubler plate repairs to ship structures. The guidelines were established using the following criteria: various stress analyses, buckling strength, corrosion types and rates, weld types, and doubler plate fatigue and fracture assessment. Studying and understanding doubler plate repair performance by comparison to that of the primary hull performance allows critical operational decisions to be made with greater ease and confidence. However, the ultimate goal of this study was to establish the design and limitations on the applications of doubler plate repairs for surface ships.

Residual Stress Effects and Predicting Crack Growth in Weldments

2016 ◽  
Vol 258 ◽  
pp. 432-435
Author(s):  
Petr Brož
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Crack Growth ◽  
Numerical Models ◽  
Limit Load ◽  
Stress Effects ◽  
R Ratio ◽  
Fatigue And Fracture ◽  
Stress Zone ◽  
Fracture Assessment

It is explained which way a welded zone integrity has to concentrate on a number of inconveniences resulting from the weld behaviour. These problems will be discussed for evaluation of fatigue and fracture. Going after the fracture assessment address, the effect of weld configuration on stress intensity factor is fixing. A pertinent input to these methods is the limit load. In the view of the prominence of residual stresses in weldments, the interpretation of combined primary and secondary stresses in fracture evaluation is most desirable to be described in great detail. The influence of residual stresses on R – ratio is given. The weldment testing methods involve the techniques for definite microstructural regions and elimination of residual stress effects on fracture toughness measuring. For FCG rate predicting, the initial residual stresses are put into numerical models and residual stress distribution is simulated, incorporating crack growth. The technique is suggested for cracks initiating within a weld, namely in tensile residual stress zone.

Design Guidelines for Doubler Plate Repairs of Ship Structures

2006 ◽  
Vol 22 (04) ◽  
pp. 219-238
Author(s):  
Pradeep K. Sensharma ◽  
Malcolm Willis ◽  
Aaron Dinovitzer ◽  
Nat Nappi
Keyword(s):  
Engineering Design ◽  
Low Cost ◽  
Design Guidelines ◽  
Performance Data ◽  
Ship Structures ◽  
Buckling Strength ◽  
Relative Ease ◽  
Fatigue And Fracture ◽  
Fracture Assessment ◽  
Design Guidance

The use of doubler plates or "doublers" has become routine for temporary ship repairs. It is the preferred method for ship structural repairs for plate corrosion due to its relative ease and low cost of installation over the more costly permanent welded plate insert repair. A lack of performance data and engineering design guidance are the reasons that repairs with doublers are currently considered only temporary. The objective of this study was to develop a set of guidelines for designing and applying doubler plate repairs to ship structures. The guidelines were established using the following criteria: various stress analyses, buckling strength, corrosion types and rates, weld types, and doubler plate fatigue and fracture assessment. Studying and understanding doubler plate repair performance by comparison to welded plate insert repair performance in the primary hull allows critical operational decisions to be made with greater ease and confidence. However, the ultimate goal of this study was to establish the design and limitations on the applications of doubler plate repairs for surface ships.

Sign in / Sign up

Export Citation Format

Share Document