Experimental fatigue crack growth analysis and modelling in part‐through circumferentially pre‐cracked pipes under pure bending load

Abstract

In the present work, an attempt has been made to study the fatigue crack growth in a part‐through circumferentially notched pipe specimen. It has been observed that under four‐point bend cyclic load, the crack propagates in a transverse plane in the radial direction initially followed by propagation in the circumferential direction. The crack extension in the circumferential direction resulted crack growth retardation in the radial direction. This behaviour of the fatigue crack growth has been modelled, and a fatigue life prediction methodology based on an exponential model has been applied for prediction of fatigue crack growth.

New shape function solutions for fracture mechanics analysis of offshore wind turbine monopile foundations

“…In order to examine the influence of / and / ratios on the shape function solution, the converged Y values at / = 40 (see Table 5) were plotted against these ratios in Figure 19. To formulate these solutions and present the results in the form of a simple equation, the observed curves in Figure 19 were interpolated using a second order polynomial fit which has been described in the general form in Equation (20), and values of A, B and C coefficients for a/t = 0.2, 0.5 and 0.8 are summarised in Table 6. Note that the polynomial interpolation between the known data points was customised in order to always have the interpolated values slightly greater, hence more conservative, than the computed value obtained from FE simulations.…”

“…Moreover, Miyamoto and Miyoshi [15] and Tan and Fenner [16] investigated stress intensity factor solutions for a semi-elliptical crack, in a finite plate using the finite element method and in pressurised cylinders using boundary integral equation method, respectively. Although various researchers have experimentally investigated the fatigue crack growth behaviour in hollow cylindrical structures with circumferential semi-elliptical cracks at the outer surface [17][18][19][20] , the only relevant fracture mechanics shape function and SIF solutions available to analyse experimental data for such geometry are those proposed by J.C. Newman & I.S. Raju (N&R) in 1986 [21].…”

Surface Crack Growth in Offshore Metallic Pipes under Cyclic Loads: A Literature Review

“…Among the literature in regard to the surface crack growth in pipes, experimental studies [12,[20][21][22][23][24][25][26], as an indispensable and important component, have been conducted on surface cracked pipes for the purpose of understanding the mechanism of surface crack growth, calibrating and validating related numerical and analytical evaluation methods. The majority of the studies focused on numerical approaches, mostly by means of the FE method [12,[27][28][29][30][31][32][33][34][35][36][37][38].…”

A computational strategy for damage‐tolerant design of hollow shafts under mixed‐mode loading condition

“…Some studies have been made concerning the prediction of the structural integrity of such cylindrical metallic components; they can be performed through fatigue growth numerical analysis, assuming initial and accumulated in service damages …”

“…Some studies have been made concerning the prediction of the structural integrity of such cylindrical metallic components; they can be performed through fatigue growth numerical analysis, assuming initial and accumulated in service damages. 2,3 The finite element (FE) in combination with the dual boundary element (DBE) methods represents a viable option to implement a global-local approach useful to investigate the fatigue behaviour of complex structural components undergoing complex loading conditions within acceptable computational time. In Citarella et al, 4 Giannella et al, 5 Citarella et al, 6 Citarella et al, 7 and Fellinger et al, [4][5][6][7][8] the synergetic combined usage of FEM and DBEM approaches when tackling crack growth problems under mixed mode conditions is shown.…”