Optimal penalty stiffness values of concurrent 2D elastic interface elements leading to accurate stress tractions

Autor: Giovanni Castellazzi, Daniela Ciancio, Ignacio Carol
Rok vydání: 2014
Předmět:
Zdroj: International Journal for Numerical Methods in Engineering. 98:344-370
ISSN: 0029-5981
DOI: 10.1002/nme.4633
Popis: SUMMARY Zero-thickness interface elements are used to model contact surfaces or potential cracks. In these cases, their elastic stiffness is often set extremely high to reproduce a rigid behavior. This paper shows that the values of the stress tractions at the nodes of these elements can be affected by an error. A new procedure is proposed here, consisting of adding some nondimensional coefficients (purely geometry-dependent) to the values of the interface stiffness parameters. Thus doing, the accurate tractions at the interface nodes are recovered. Copyright © 2014 John Wiley & Sons, Ltd. Interface elements are zero-thickness (equivalent to a line in 2D and an area in 3D) finite elements (FE) characterized by two surfaces connected to each other that detach in the deformed configuration. They are treated and implemented like standard FE. According to the displacement- based FE approach, their displacement field (the relative displacement between the two surfaces) is interpolated by means of shape functions and nodal displacement values. They can be easily inserted along the mesh lines of a standard FE mesh and assembled in the context of the FE analysis. Their applications cover a wide range of cases, such as the simulation of the mechanical behavior of joints, bonding surfaces, or cracks. They are often applied for the representation of strong discontinuities in the displacement field of a fractured continuum. Their constitutive law is commonly defined in terms of stress-displacement relationships. This means that the deformed configuration of an interface element generates the detachment of the interface surfaces and the separation of the neighboring continuum elements connected to them. This condition reproduces reasonably the discontinuities generated by the formation of a crack or the de-bonding of a joint. Sometimes, the opening of an interface element may be ruled by cohesive laws that allows for the transmission of cohesive stresses after the opening. The situation prior to the damage onset, in which the opening of an interface means the opening of a crack or other dissipative localization phenomena, may be characterized by two different situations
Databáze: OpenAIRE
Externí odkaz: