A singular planar element with rotational degree of freedom for fracture analysis. (December 2016)

• Record Type: Journal Article
• Authors: Xing, Chen; Zhou, Chuwei
• Is Part Of: Theoretical and applied fracture mechanics. Volume 86:Part B(2016)
• Page Start: 239
• Page End: 249
• Publication Date: 2016-12
• Subjects: In-plane rotational DOF -- Singular finite element -- Displacement function -- Crack -- Stress intensity factor; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2016.07.011
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: It is the first time to propose a singular planar element including rotational DOF. It can be used in crack simulation linking with ordinary Allman element. In all cases, it achieves much better results than 5-node QPE. In shell problem, it is more accurate and efficient than 6-node QPE. Abstract: A triangle singular planar element with corner node rotational degree of freedom (DOF) is developed for crack tip field analysis. On this element's two sides adjacent to crack tip, quarter point nodes with only tangent DOF are employed to generate tangential r 1/2 displacement. Meanwhile, interpolated by both corner nodal translational and rotational DOFs, a normal displacement with r 1/2 term is constructed on these two sides. On the non-singular side of this element a displacement function equivalent to that of Allman element is also proposed. Singularities predicted by this singular element have been proven obviously more accurate than those predicted by 5-node quarter-point element (QPE). For planar problem, though accuracy of this singular element is slightly inferior to that of 6-node QPE under coarse mesh, it rapidly approaches the latter with mesh refining. When applied in shell structure, models employing the proposed element can achieve more accurate results than those using 6-node QPE even with less total DOFs.