Open Access

ARTICLE

S. N. Atluri¹
Structural Durability & Health Monitoring, Vol.1, No.1, pp. 1-20, 2005, DOI:10.3970/sdhm.2005.001.001
Abstract The solution of three-dimensional cracks (arbitrary surfaces of discontinuity) in solids and structures is considered. The BEM, developed based on the symmetric Galerkin BIEs, is used for obtaining the fracture solutions at the arbitrary crack-front. The finite element method is used to model the uncracked global (built-up) structure for obtaining the stresses in an otherwise uncracked body. The solution for the cracked structural component is obtained in an iteration procedure, which alternates between FEM solution for the uncracked body, and the SGBEM solution for the crack in the local finite-sized subdomain. In addition, some crack growth models are used to… More >

View

1345

Download

1105

Open Access

ARTICLE

G. Dhondt¹
Structural Durability & Health Monitoring, Vol.1, No.1, pp. 21-34, 2005, DOI:10.3970/sdhm.2005.001.021
Abstract An algorithm is described which allows for the automatic calculation of crack propagation due to cyclic loading under mixed-mode conditions. The core of the procedure deals with the insertion of an arbitrarily formed crack into a virgin 20-node brick element mesh, thereby generating new quadratic bricks. One especially difficult aspect is the extension of the triangulation of the crack surface up to the boundary of the crack front elements. In the present article the technique is applied to linear elastic calculations using the stress intensity factor concept and a Paris-type law. However, other crack propagation parameters and crack propagation laws… More >

View

1312

Download

996

Open Access

ARTICLE

D. Gross¹, T. Rangelov², P. Dineva³
Structural Durability & Health Monitoring, Vol.1, No.1, pp. 35-48, 2005, DOI:10.3970/sdhm.2005.001.035
Abstract Scattering of time harmonic waves by a finite crack in a homogeneous piezoelectric plane under plane strain conditions is studied. Using generalized displacements and tractions, the problem is described by a non-hypersingular traction based boundary integral equation method (BIEM). The fundamental solution is derived in closed form by Radon transforms. As a typical example, the procedure is applied to a straight crack under incident longitudinal waves and under vertically polarized shear waves. The K-factor results are compared with those from the literature for a special case. Furthermore, their dependence on parameters like frequency, angle of incidence, wave type and material… More >

View

1349

Download

1069

Open Access

ARTICLE

P. Horst¹
Structural Durability & Health Monitoring, Vol.1, No.1, pp. 49-66, 2005, DOI:10.3970/sdhm.2005.001.049
Abstract The paper presents a Monte Carlo Simulation method for the assessment of Multiple Site Damage (MSD) and a subsequent attempt to find a way to interpret intermediate results of the Monte Carlo Simulation with respect to the criticality of scenarios. The basic deterministic part of the model is based on the compounding method, which is used in order to gain an acceptable computational effort. Some examples illustrate features of MSD scenarios and this allows to check an approach for feature detection via Wavelet transforms. This Wavelet transform approach shows some positive results in the interpretation of MSD scenarios. More >

View

1460

Download

1096

Open Access

ARTICLE

M. Mashayekhi¹, S. Ziaei-Rad², J. Parvizian³, K. Nikbin¹, H. Hadavinia¹
Structural Durability & Health Monitoring, Vol.1, No.1, pp. 67-82, 2005, DOI:10.3970/sdhm.2005.001.067
Abstract The continuum mechanical simulation of microstructural damage process is important in the study of ductile fracture mechanics. An essential feature in these analyses, is the strong influence of stress triaxiality ratio, i.e. the ratio of mean stress to equivalent stress, on the rate of damage growth. In this paper, finite element simulation of damage evolution and fracture initiation in ductile solids will be investigated. A fully coupled constitutive elastic-plastic-damage model has been implemented. The stress update algorithm for the constitutive model is presented together with the consistent tangent operator, which is needed for implicit FEA. Simulations are performed and the… More >

View

1578

Download

1376

Open Access

ARTICLE

R. Moskovic¹, P. E. J. Flewitt^1,2
Structural Durability & Health Monitoring, Vol.1, No.1, pp. 83-94, 2005, DOI:10.3970/sdhm.2005.001.083
Abstract Consideration of the structural integrity is one of the inputs when evaluating potential solutions to plant problems. Structural integrity assessments of components forming the pressure boundaries of nuclear plant evaluate safety margins against cleavage fracture. These assessments consider the reserve factors between the applied stress and fracture toughness of the material as well as temperature margins between the operating temperature and the temperature at which the steel is ductile as defined by upper shelf behaviour. To carry out these structural integrity assessments, estimates of cleavage fracture toughness are required. The approach presented in this paper allows for differences between cleavage… More >

View

1424

Download

1198