The Energy Release Rate of the Fiber/Polymer Matrix Interface: Measurement and Theoretical Analysis

1997 ◽  
Vol 16 (4) ◽  
pp. 341-352 ◽  
Author(s):  
A. Hampe ◽  
C. Marotzke
2020 ◽  
Vol 54 (21) ◽  
pp. 3021-3034
Author(s):  
Luca Di Stasio ◽  
Janis Varna ◽  
Zoubir Ayadi

Models of Representative Volume Elements of cross-ply laminates with different geometric configurations and damage states are studied. Debond growth is characterized by the estimation of the Mode I and Mode II Energy Release Rate using the Virtual Crack Closure Technique. It is found that the presence of the [Formula: see text] interface and the thickness of the [Formula: see text] layer has no effect, apart from laminates with ultra-thin [Formula: see text] plies where it is however modest. The present analysis supports the claim that debond growth is not affected by the ply-thickness effect.


2019 ◽  
Author(s):  
Luca Di Stasio ◽  
Janis Varna ◽  
Zoubir Ayadi

Models of Representative Volume Elements (RVEs) of cross-ply laminates with different geometric configurations and damage states are studied. Debond growth is characterized by the estimation of the Mode I and Mode II Energy Release Rate (ERR) using the Virtual Crack Closure Technique (VCCT). It is found that the presence of the 0° /90° interface and the thickness of the 0° layer have no effect, apart from laminates with ultra-thin 90° plies where it is however modest. The present analysis supports the claim that debond growth is not affected by the ply-thickness effect.


2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Pengfei Guo ◽  
Kengkeng Ye ◽  
Xiaohu Zhang

Shaped energy blasting has been widely used in the field of geotechnical engineering because of its good orientation and high energy utilization. However, the bifurcation of cracks in the direction of energy accumulation seriously affects the precracking effect in the direction of energy accumulation. In order to study the influence of the shaped energy angle on the crack propagation and bifurcation in the direction of energy accumulation, this paper used theoretical analysis and numerical simulation to study the influence of the energy angle on the crack propagation law in the energy-concentration direction. It was found that the energy release rate in the direction of energy accumulation after blasting was the main determinant of crack propagation and bifurcation in the direction of energy accumulation, and it decreased with the increase of the shaped energy angle. When the energy release rate in the direction of energy absorption exceeded a certain critical value, the stress intensity factor K at the crack tip would be affected by the impact load more than the bifurcation toughness KB, resulting in bifurcation of the crack in the direction of the energy. The SPH method was used to simulate and analyze the energy blasting of four different shaped energy angles. The results show that as the shaped energy angle increases when the shaped energy angle is greater than or equal to 35°, the cracks in the direction of energy accumulation after blasting are bifurcated, two cracks at the crack tip. When the shaped energy angle is less than 24°, only one horizontal crack is generated in the direction of shaped energy, which is in good agreement with the theoretical analysis. The research in this paper will provide a certain research basis for the design of the blasting device and the optimization of the blasting effect.


2018 ◽  
Vol 46 (3) ◽  
pp. 130-152
Author(s):  
Dennis S. Kelliher

ABSTRACT When performing predictive durability analyses on tires using finite element methods, it is generally recognized that energy release rate (ERR) is the best measure by which to characterize the fatigue behavior of rubber. By addressing actual cracks in a simulation geometry, ERR provides a more appropriate durability criterion than the strain energy density (SED) of geometries without cracks. If determined as a function of crack length and loading history, and augmented with material crack growth properties, ERR allows for a quantitative prediction of fatigue life. Complications arise, however, from extra steps required to implement the calculation of ERR within the analysis process. This article presents an overview and some details of a method to perform such analyses. The method involves a preprocessing step that automates the creation of a ribbon crack within an axisymmetric-geometry finite element model at a predetermined location. After inflating and expanding to three dimensions to fully load the tire against a surface, full ribbon sections of the crack are then incrementally closed through multiple solution steps, finally achieving complete closure. A postprocessing step is developed to determine ERR as a function of crack length from this enforced crack closure technique. This includes an innovative approach to calculating ERR as the crack length approaches zero.


Sign in / Sign up

Export Citation Format

Share Document