The UniGrow model is an analytical procedure to assess the fatigue crack growth based on elastic–plastic tip stresses and strains. assumption that (FCG) can be considered as a process of successive re-initiations resulting from material damage in zone. main parameters this are radius elementary block size. Experimental FCG data obtained for S355 carbon steel showed assuming size with same value...

A technique for modelling arbitrary discontinuities in nite elements is presented. Both discontinuities in the function and its derivatives are considered. Methods for intersecting and branching discontinuities are given. In all cases, the discontinuous approximation is constructed in terms of a signed distance functions, so level sets can be used to update the position of the discontinuities. ...

Commercial finite element software generally includes dedicated numerical models for the nonlinear response of concrete under loading. These models usually include a smeared crack analogy to account for the relatively poor tensile strength of concrete, a plasticity algorithm to facilitate concrete crushing in compression regions and a method of specifying the amount, the distribution and the or...

Among the many requirements for the design of gas turbine engine components,understanding of the behaviour of these components and the alloys used to make themis fundamental in order to ensure structural integrity and safe operation of theengines. In this paper, the conventional Safe Life Approach is discussed togetherwith an overview of crack growth modelling used at Pratt it W...

We consider the occurrence of unimodular eigenvalues for palindromic eigenvalue problems associated with the matrix polynomial Pn(λ) ≡ ∑n i=0Aiλ i where Ai = An−i with M∗ ≡ M , M or PMP (P 2 = I). From the properties of palindromic eigenvalues and their characteristic polynomials, we show that eigenvalues are not generically excluded from the unit circle, thus occurring quite often, except for ...

An assessment of the plasticity-induced crack-closure concept is made, in light of some of the questions that have been raised on the validity of the concept, and the assumptions that have been made concerning crack-tip damage below the crack-opening stress. The impact of using other crack-tip parameters, such as the cyclic crack-tip displacement, to model crack-growth rate behavior was studied...

poor stand establishment of canola (brassica napus l.) under flatland mechanized planting and crust-forming soil is a major problem for farmers in central iran. previous research there showed that irrigated cotton emergence on crust-forming soils under flatland planting can be significantly improved using a double-disk planter with zero-pressure press wheel tires and no crust-breaking. in that ...

A novel FFT-based phase-field fracture framework for modelling fatigue crack initiation and propagation at the microscale is presented. damage driving force defined based on stored energy dislocation density, relating with microstructural damage. The formulation numerically implemented using FFT methods to enable of sufficiently large, representative 3D regions. early stages cracking are simula...