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Abstract: This study offers novel progresses for a semianalytical method to simulate 2D propagation of cracks based on linear elastic fracture mechanics. For this purpose, a new algorithm is proposed on the basis of the linear elastic fracture mechanics for crack propagation in single‐mode and mixed mode. Herein, discretization is only performed on the boundaries of the problem by using specific subparametric elements and higher‐order Chebyshev polynomials as mapping functions. Implementing the weighted residual method and by taking Clenshaw‐Curtis numerical quadrature, diagonal Euler's differential equations are obtained. Consequently, once the local coordinate origin is assumed at the tip of the crack, the stress intensity factors can be derived directly. In accordance with the rate of maximum energy release as a propagation criterion and by proposing a new quasi‐automatic remeshing procedure based on domain division, the crack propagation is applied here. Based on the new presented algorithm, application of the new semianalytical method to crack propagation analysis is more flexible and efficient. By taking this advantage, relatively coarse and simple discretization compared with other computational methods may be used. By modelling 4 benchmark problems with a few numbers of degrees of freedom, the validity and accuracy of the current method is illustrated. Results show that the presented algorithm is applicable for efficient and precise prediction of crack trajectories. [ABSTRACT FROM AUTHOR]

This study presents a novel development of a new semi-analytical method with diagonal coefficient matrices to model crack issues. Accurate stress intensity factors based on linear elastic fracture mechanics are extracted directly from the semi-analytical method. In this method, only the boundaries of problems are discretized using specific subparametric elements and higher-order Chebyshev mapping functions. Implementing the weighted residual method and using Clenshaw-Curtis numerical integration result in diagonal Euler's differential equations. Consequently, when the local coordinates origin is located at the crack tip, the stress intensity factors can be determined directly without further processing. In order to present infinite stress at the crack tip, a new form of nodal force function is proposed. Validity and accuracy of the proposed method is fully demonstrated through four benchmark problems, which are successfully modeled using a few numbers of degrees of freedom. The numerical results agree very well with the analytical solution, experimental outcomes and the results from existing numerical methods available in the literature. [ABSTRACT FROM AUTHOR]

Pre-eclampsia, as one of the most critical pregnancy complications, considered as a common cause of death in the prenatal period. The placental position had no significant association with pre-eclampsia, but there was a significant association between pre-eclampsia and placental thickness, and pre-eclampsia cases had a thicker placenta than normal group (P = 0.038). Placental thickness which is easily assessed at middle trimester of pregnancy by routine screening ultrasonography, could be an ideal predictive tool for evaluating the risk of developing pre-eclampsia. [Extracted from the article]

An abstract of the conference paper "Isolated first trimester uterine artery screening fails to predict severe cases of placental dysfunctions," by L. Adams and colleagues is presented.