Degradation law of mixed-mode (I/II) fracture toughness of sandstone under drying-wetting cycles in acid and alkaline environments

2021 ◽  
Vol 14 (14) ◽  
Author(s):  
Hong Liang ◽  
Wen Yuan ◽  
Yan Fu ◽  
Xinrong Liu ◽  
Yingkun Xie
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Mode I ◽  
Alkaline Environments

scholarly journals Mixed-Mode Interlaminar Fracture Toughness of Glass and Carbon Fibre Powder Epoxy Composites—For Design of Wind and Tidal Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2103
Author(s):  
Christophe Floreani ◽  
Colin Robert ◽  
Parvez Alam ◽  
Peter Davies ◽  
Conchúr M. Ó. Brádaigh
Keyword(s):  
Fracture Toughness ◽  
Carbon Fibre ◽  
Composite Structures ◽  
Mixed Mode ◽  
Epoxy Composites ◽  
Mode I ◽  
Mode Ii ◽  
Pure Mode ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture

Powder epoxy composites have several advantages for the processing of large composite structures, including low exotherm, viscosity and material cost, as well as the ability to carry out separate melting and curing operations. This work studies the mode I and mixed-mode toughness, as well as the in-plane mechanical properties of unidirectional stitched glass and carbon fibre reinforced powder epoxy composites. The interlaminar fracture toughness is studied in pure mode I by performing Double Cantilever Beam tests and at 25% mode II, 50% mode II and 75% mode II by performing Mixed Mode Bending testing according to the ASTM D5528-13 test standard. The tensile and compressive properties are comparable to that of standard epoxy composites but both the mode I and mixed-mode toughness are shown to be significantly higher than that of other epoxy composites, even when comparing to toughened epoxies. The mixed-mode critical strain energy release rate as a function of the delamination mode ratio is also provided. This paper highlights the potential for powder epoxy composites in the manufacturing of structures where there is a risk of delamination.

Experimental and theoretical fracture toughness investigation of PUR foams under mixed mode I+III loading

2018 ◽  
Vol 67 ◽  
pp. 75-83 ◽  
Author(s):  
M.R.M. Aliha ◽  
E. Linul ◽  
A. Bahmani ◽  
L. Marsavina
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Mode I

scholarly journals Low temperature mixed-mode debond fracture and fatigue characterisation of foam core sandwich

2018 ◽  
Vol 22 (4) ◽  
pp. 1039-1054 ◽  
Author(s):  
Arash Farshidi ◽  
Christian Berggreen ◽  
Leif A Carlsson
Keyword(s):  
Fracture Toughness ◽  
Growth Rate ◽  
Low Temperature ◽  
Mixed Mode ◽  
Room Temperature ◽  
Sliding Mode ◽  
Fatigue Tests ◽  
Mode I ◽  
Foam Core ◽  
Climatic Chamber

This paper experimentally investigates the effects of low temperature on fracture toughness and fatigue debond growth rate in foam core sandwich composites. Mixed-mode bending specimens were statically and cyclically tested inside a climatic chamber at a low temperature (−20°C) and at room temperature (23°C) as a reference. Testing was conducted in mode I (opening) and mixed-mode I/II (opening-sliding) mode mixities. The fatigue tests results are presented according to the modified Paris–Erdogan relation. Results showed substantial fracture toughness reduction due to low temperature. Low temperature furthermore elevated the cyclic crack growth rate.

The influence of natural and synthetic fibers on mixed mode I/II fracture behavior of cement concrete materials

2019 ◽  
Vol 46 (12) ◽  
pp. 1081-1089 ◽  
Author(s):  
Hossein Karimzadeh ◽  
Ali Razmi ◽  
Reza Imaninasab ◽  
Afshin Esminejad
Keyword(s):  
Fracture Toughness ◽  
Reinforced Concrete ◽  
Mixed Mode ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Synthetic Fiber ◽  
Mode I ◽  
Fiber Reinforced ◽  
Synthetic Fibers ◽  
Natural And Synthetic

This paper evaluated mixed mode I/II fracture toughness of fiber-reinforced concrete using cracked semi-circular bend (SCB) specimens subjected to three-point bending test. Additionally, a comparison was made between the experimental results and the estimations made by different theoretical criteria. Natural and synthetic fibers at various concentrations were used in this study. After producing cracks in SCB specimens at different inclination angles to induce different mixed mode loading conditions (from pure mode I to II), the fracture toughness of SCB specimens was determined. Furthermore, the compressive, splitting tensile, and flexural strength of natural and synthetic fiber-reinforced concrete were measured after 7 and 28 days of curing. While there is an increase in the aforementioned strengths with fiber content increase, 0.3% was found to be the optimum percentage regarding fracture toughness for both fibers. Also, the comparison between the experimental and theoretical results showed that generalized maximum tangential stress criterion estimated the experimental data satisfactorily.

Fracture toughness analysis of HCCD specimens of Longmaxi shale subjected to mixed mode I-II loading

2020 ◽  
Vol 239 ◽  
pp. 107299 ◽  
Author(s):  
Hui Wang ◽  
Yong Li ◽  
Shugang Cao ◽  
Nicholas Fantuzzi ◽  
Ruikai Pan ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Mixed Mode ◽  
Mode I ◽  
Longmaxi Shale

Effect of mixed mode I/III loading on fracture toughness of 7010 aluminium alloy

2006 ◽  
Vol 22 (1) ◽  
pp. 91-96 ◽  
Author(s):  
K. S. S. Eswar Raju ◽  
A. K. Mukhopadhyay ◽  
S. V. Kamat
Keyword(s):  
Fracture Toughness ◽  
Aluminium Alloy ◽  
Mixed Mode ◽  
Mode I
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