Investigation of mode-II delamination fracture energy with a discontinuous computational homogenization model

Numerical methods for delamination analysis, such as the cohesive zone method, require fracture energy as an essential input. Existing formulations rely on a phenomenological relationship that links fracture energy to the mode of fracture based on linear elastic fracture mechanics (LEFM). However, doubts exist about the applicability of LEFM....

Experimental characterisation of flexural bond behaviour in brick masonry

The brick-to-mortar bond often represents the weakest link leading to cracking and failure of masonry structures. For this reason, the in-situ characterization of masonry’s flexural bond behaviour (here defined as flexural bond strength and flexural bond fracture energy), is essential for the assessment of existing buildings. Among masonry...

Characterization of mode-II delamination fracture energy via computational homogenization

Due to the complex underlying microscopic damage processes, the failure behavior of composite materials is challenging to understand and predict. Fracture mechanics approaches [1] and cohesive zone models [2] that simulate delamination generally consider the fracture energy as a material characteristic that exclusively depends on the fracture...

Effect of cyclic aging on mode I fracture energy of dissimilar metal/composite DCB adhesive joints

In some industrial applications, adhesive joints are cyclically exposed to a moist environment, where cyclic moisture absorption and desorption can significantly alter the fracture energy of the bonded joints. Most previous studies are based on monotonic aging conditions, while the performance of bonded joints under cyclic aging is not well...

A study on fracture toughness of ultra-high toughness geopolymer composites based on double-K criterion

Ultra-high toughness geopolymer composites (UHTGC) were fabricated based on the matrix of binder composed of alkali-activated fly-ash and granulated blast furnace slag and polyvinyl alcohol (PVA) fibres in this research. The tensile behaviour and fracture toughness of UHTGC are investigated on both macro and microscales experimentally and...

Material Characterization Approach for Modeling High-Strength Concrete after Cooling from Elevated Temperatures

Advanced numerical modeling of high-strength concrete (fc>60 MPa) structures designed to withstand severe thermal conditions requires detailed and reliable information on the mechanical properties of the material exposed to elevated temperatures. The only uniaxial compressive strength variation with temperature is not enough to satisfy the...

Modeling of dynamic mode I crack growth in glass fiber-reinforced polymer composites: fracture energy and failure mechanism

The mode-I dynamic fracture energy and failure mechanisms of glass fiber-reinforced polymer composites are investigated with an embedded cell model of the single-edge-notched-tension (SENT) geometry. Under an applied dynamic loading, a crack may propagate in the embedded microstructure, accompanied by the development of a fracture process...

Determination of fracture energy of early age concrete through a uniaxial tensile test on an un-notched specimen

Unlike the notched specimens for conventional concrete fracture tests, this paper introduces a deformation-controlled uniaxial tensile test on an un-notched specimen. The surface of the dog bone-shaped specimen is a second order parabolic curve, and the gradual change in the specimen shape does not lead to extreme stress concentrations....

Determination of fracture strength and fracture energy of (metallo-) ceramics by a wedge loading methodology and corresponding cohesive zone-based finite element analysis

A wedge loaded testing methodology to determine the fracture energy and strength of (semi-) brittle (metallo-)ceramics is presented. The methodology combines a tailored specimen geometry and a comprehensive finite element analysis based on cohesive zone modelling. The use of a simulation-based approach to extract both fracture strength and...

A mesoscale modelling perspective of cracking process and fracture energy under high strain rate in tension

This paper presents a numerical modelling study on the simulation of the cracking process and fracture energy in concrete under high strain rate. To capture the stress wave effect and the damage evolution at the meso-length scale, both a homogeneous model with a millimetreresolution mesh and an explicit heterogeneous mesoscale model with random...

A plane stress softening plasticity model for orthotropic materials

Failure in plain and reinforced concrete - An analysis of crack width and crack spacing

Fracture mechanics of concrete: Will applications start to emerge?

Fracture mechanics of concrete has developed into an active field of research in the past decades. It promises a rational solution technique to structural problems in reinforced concrete in the limit state. Numerical tools have been developed on the basis of fracture mechanics theories. The question to be addressed is how much of the early...