Process zone analysis for the single-edge notched specimen: Part II. Process zone growth and crack propagation

1991 ◽  
Vol 49 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Rasko P. Ojdrovic ◽  
Henry J. Petroski
Keyword(s):  
Crack Propagation ◽  
Process Zone ◽  
Single Edge ◽  
Notched Specimen ◽  
Zone Growth

Study on Interfacial Crack Propagation and Fracture between Embedded Steel and HSHPC

2007 ◽  
Vol 348-349 ◽  
pp. 853-856
Author(s):  
Shan Suo Zheng ◽  
Lei Li ◽  
Guo Zhuan Deng ◽  
Liang Zhang
Keyword(s):  
Crack Propagation ◽  
High Performance ◽  
Fracture Process ◽  
Fracture Process Zone ◽  
High Performance Concrete ◽  
Process Zone ◽  
Interfacial Crack ◽  
High Strength ◽  
Interfacial Fracture ◽  
Softening Process

Steel reinforced high strength and high performance concrete (SRHSHPC) specimens were experimented to study the mechanical behaviors between steel and concrete interface. In experiment, interfacial bond softening process was observed, which can be explained in terms of damage along the interface, leading to progressive reduction of shear transfer capability between steel and high strength and high performance concrete (HSHPC). In this paper, bond softening process along the interface is considered in the analysis of crack-induced debonding. Interfacial bond-slip mechanism between steel and HSHPC is studied in detail based on fracture mechanics. With the help of acoustic emissions technology, the crack propagation in the interlayer was observed, thus the interfacial crack propagation and fracture model is set up. Under the assumption that the interlayer is weak concrete compared with concrete matrix, the stress field as well as displacement field around the crack tip is deduced. The characteristics of interfacial fracture process are discussed and a model for interfacial fracture process zone is built up. With this model, the size of fracture process zone can be derived. At last, the influence of the fracture process zone on interfacial fracture toughness is determined using critical fracture toughness. All these may contribute to improvement of theory for SRHSHPC composite structure.

scholarly journals Investigation of mixed mode fatigue crack propagation in SEN-specimen under in-phase and out-of-phase conditions due to tension-compression and torsional loading

2019 ◽  
Vol 300 ◽  
pp. 11006
Author(s):  
Paul Koester ◽  
Christopher Benz ◽  
Manuela Sander
Keyword(s):  
Crack Propagation ◽  
Mixed Mode ◽  
Testing Machine ◽  
Theoretical Background ◽  
Residual Lifetime ◽  
Single Edge ◽  
Notched Specimens ◽  
Precise Knowledge ◽  
Twisting Angle ◽  
Phase Angles

Numerous cases of damage by fatigue in structures are related to mechanical stresses due to mixed mode loading conditions. To prevent such cases of failure a precise knowledge of the corresponding theoretical background is indispensable. Unfortunately, it is not yet possible to describe the crack propagation considering a superposition of all three crack modes satisfactory. For this purpose, experiments on single-edge notched specimens made of 34CrNiMo6 using a tension-torsion testing machine under different mixed mode ratios and phase angles were performed. The focus of the investigations is especially on the kinking and the twisting angle of the crack as well as on the influence on the residual lifetime. Further, existing concepts concerning the prediction of the crack growth under mixed mode are evaluated.

The Critical Load Measurements of Pineapple Leaf Fibre Reinforced Polyester Composite Using Single Edge Notched Beam (SENB) Testing

2016 ◽  
Vol 1 ◽  
Author(s):  
Hendery Dahlan
Keyword(s):  
Composite Material ◽  
Crack Propagation ◽  
Critical Load ◽  
Fibre Orientation ◽  
Initial Crack ◽  
Single Edge ◽  
Main Attention ◽  
Good Resistance ◽  
Tensile Impact ◽  
Polyester Composite

<h1><strong>Pineapple leaf fibre has potential as reinforcement in composite material due to their advantages such as renewable fibre and abundantly available. Some studies have been conducted relating to their mechanical properties using tensile, impact and bending testing. However the analysis of crack propagation in pineapple leaf fibre reinforced polyester composite is still limited. In this paper, the main attention is therefore the critical load leading to crack propagation in the composite material for two different fibre orientations. The crack propagation is investigated using single edge notched beam (SENB) testing. The composite material was manufactured by hand lay-up with two different nonwoven fibre orientations i.e. 0o/90oand +45o/-45o. Then, five different initial crack lengths are given in experimental specimen. The result reveals that increasing initial crack length will decrease the value of critical load for both fibre orientations. Furthermore, the fibre orientation influences the critical loading. In general the critical load leading to crack propagation for composite with +45o/-45o orientation has higher value than composite with 0o/90o orientation. It can be concluded that the composite material with +45o/-45o orientation has good resistance to the crack growth.<br /></strong></h1>

scholarly journals FINITE ELEMENT MODELING OF THE CRACK PROPAGATION IN RC BEAMS BY USING ENERGY APPROACH

2015 ◽  
pp. 211-217
Author(s):  
Shahriar Shahbazpanahi ◽  
Chia Paknahad
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Cohesive Zone Model ◽  
Process Zone ◽  
Mesh Size ◽  
Energy Dissipation Rate ◽  
Energy Approach ◽  
Interface Element ◽  
Zone Model ◽  
Steel Bars

In present study, an interface element with nonlinear spring is used to simulate cohesive zone model (CZM) in reinforced concrete (RC) beam for Mode I fracture. The virtual crack closure technique (VCCT) is implemented to model the propagation of the fracture process zone (FPZ). This model can be calculated the energy release rate by using new method from energy approach. Energy dissipation rate by steel bars is obtained to affect on the crack propagation criterion to implement in finite element method. The numerical results are compared with references result available in the literature. It is observed that the FPZ is increased linearly and then stay constant. It may be due to effect of steel bars or inherent behavior of FPZ. The results show that the proposed model does not depend on mesh size.

Novel Estimation of Critical Frontal Process Zone of Ceramics by a Single-Edge V-Notched-Beam Technique

2007 ◽  
Vol 280-283 ◽  
pp. 1745-1750
Author(s):  
Chun Hong Chen ◽  
Hideo Awaji
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Critical Size ◽  
Process Zone ◽  
Porous Alumina ◽  
Local Stress ◽  
Zone Size ◽  
Single Edge ◽  
Frontal Process ◽  
Notch Tip

A novel estimation for the critical size of the frontal process zone of ceramics is proposed using a single-edge V-notched beam (SEVNB) technique. A three-point flexure test is carried out on aluminum titanate ceramics containing a sharp V-shaped notch with different depth. An exact solution of the critical local stress is analyzed at a critical distance from the notch tip. The critical frontal process zone size is determined as the distance between the notch tip and the point where the critical local stress equals the flexural strength of specimens without notches, based on the local fracture criterion and the Griffith-Irwin criterion. The critical size of the frontal process zone, the fracture toughness and the flexural strength were also estimated for several materials, such as, alumina, porous alumina, and alumina-based nanocomposites. The relationship between these mechanical properties indicated that there was an almost linear relationship between the fracture toughness and the resultant of strength and square root of the critical frontal process zone size, and that both of them must be increased to improve the fracture toughness of ceramics.

scholarly journals Effect Range of the Material Constraint in Different Strength Mismatched Laboratory Specimens

2020 ◽  
Vol 10 (7) ◽  
pp. 2434 ◽  
Author(s):  
Yue Dai ◽  
Jie Yang ◽  
Haofeng Chen
Keyword(s):  
Crack Propagation ◽  
Fracture Resistance ◽  
Compact Tension ◽  
Propagation Path ◽  
Resistance Curve ◽  
Single Edge ◽  
Integrity Assessment ◽  
Scientific Support ◽  
Resistance Curves ◽  
Initial Cracks

Different strength mismatched laboratory specimens that contain the compact tension (CT), single edge-notched tensile (SENT), and central-cracked tension (CCT) specimens with various specimen geometries, loading configurations, and initial cracks were selected to investigate the effect range of the material constraint systematically. The results showed that the effect range of material constraint exists in all the strength mismatched specimens and structures. The numerical value of the effect range is influenced by the geometry constraint. The high geometry constraint reduces the effect range of material constraint. When a material is located outside the effect range of material constraint, the fracture resistance curves and crack propagation paths of the specimens and structures are no longer influenced by the mechanical properties of the material. In addition, an interaction exists between the geometry constraint and material constraint. The high geometry constraint strengthens the effect of material constraint, whereas the fracture resistance curve and crack propagation path are insensitive to the material constraint under the low geometry constraint. The results in this study may provide scientific support for the structure integrity assessment and the design of strength mismatched structures.

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