Fracture mechanics in design and service: ‘living with defects’ - Fracture mechanics and the design of wood structures

1981 ◽  
Vol 299 (1446) ◽  
pp. 217-226 ◽  
Keyword(s):  
Fracture Mechanics ◽  
Wood Products ◽  
Design Codes ◽  
Wood Structures ◽  
Linear Elastic ◽  
Orthotropic Elasticity ◽  
Potential Benefits ◽  
Elastic Fracture ◽  
Mechanics Concepts ◽  
Timber Engineering

Applications of linear-elastic fracture mechanics concepts for treating brittle fracture of wood and wood products are discussed. The influence of orthotropic elasticity and heterogeneity of wood structure on the computational and experimental aspects of wood fracture are introduced. Several applications of fracture mechanics for the development of design criteria in timber engineering are discussed to illustrate the potential benefits of application of fracture mechanics in design codes.

Fracture Mechanics of Composite Materials

1978 ◽  
Vol 100 (3) ◽  
pp. 233-247 ◽  
Author(s):  
C. K. H. Dharan
Keyword(s):  
Composite Materials ◽  
Fracture Mechanics ◽  
Fiber Orientation ◽  
Linear Elastic Fracture Mechanics ◽  
Orthotropic Materials ◽  
Isotropic Materials ◽  
Linear Elastic ◽  
Fiber Reinforced Materials ◽  
Elastic Fracture ◽  
Mechanics Concepts

The applicability of fracture mechanics to conventional isotropic materials has been well demonstrated. For fiber-reinforced materials, however, fracture mechanics investigations have met with mixed results. For collinear crack extension of a crack on a plane of symmetry in orthotropic materials, fracture behavior has been successfully predicted using linear elastic fracture mechanics concepts; however, extrapolation to other fiber orientation combinations has been less successful. This is because fracture in anisotropic materials is more complex than in isotropic materials and is governed by additional parameters such as fiber orientation, lamination order and the constitutive relations that describe the mechanical responses of the fiber, the matrix and the interface. This paper reviews the fundamentals of fracture mechanics for isotropic materials and discusses its extension to orthotropic materials. This is followed by a discussion of the variety of failure modes observed in composites and a review of the predominant fracture mechanics theories that attempt to predict fracture using semi-empirical parameters. The main aim of this paper is to present a survey of the field in its current state and to demonstrate the approach taken by each investigator. The paper concludes with two examples where linear elastic fracture mechanics concepts have been satisfactorily employed for composite materials.

Fracture Mechanics Assessment of Hydrogen Storage Vessel

2021 ◽  
Author(s):  
Xiaoliang Jia ◽  
Zhiwei Chen ◽  
Fang Ji
Keyword(s):  
High Pressure ◽  
Fracture Mechanics ◽  
Hydrogen Storage ◽  
High Strength Steel ◽  
High Strength ◽  
Linear Elastic Fracture Mechanics ◽  
Storage Vessel ◽  
Linear Elastic ◽  
Elastic Fracture ◽  
Hydrogen Storage Vessel

Abstract High strength steel is usually used in fabrication of hydrogen storage vessel. The fracture toughness of high strength steel will be decreased and the crack sensitivity of the structures will be increased when high strength steels are applied in hydrogen environment with high pressure. Hence, the small cracks on the surface of pressure vessel may grow rapidly then lead to rupture. Therefore, this paper makes a series of research on how to evaluate the 4130X steel hydrogen storage vessel with fracture mechanics. This study is based on the assumption that there is a semi-elliptic crack on internal surface of hydrogen storage vessel. First of all, based on linear elastic fracture mechanics, the stress intensity factors and crack tolerance of 4130X steel hydrogen storage vessel have been calculated by means of finite element method based on interaction integral theory and polynomial-approximated approach from GB/T 34019 Ultra-high pressure vessels. Then, a comparative study has been made from the results of above methods to find out the difference between them. At last, the fatigue life of a 4130X steel hydrogen storage vessel has been predicted based on linear elastic fracture mechanics and Paris formula. The calculation methods and analysis conclusion can be used to direct the design and manufacture of hydrogen storage vessel.

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