A DCAMM seminar will be presented by
Pawel B. Woelke, Ph.D., PE
Weidlinger Associates Inc.
New York, USA
Abstract:
The focus of the presentation is on finite element investigation of structural response to various loading conditions leading to extensive failure which renders the structure unable to perform its function. Since, in many cases, structural failure initiates on the micromechanical level of the material, the issue of bridging the length scales between micromechanics and large-scale structures is discussed. Effective modelling of failure on a structural scale restricts the type of the finite elements used in the analyses to shell elements with in-plane dimension larger than the thickness. Thus, we consider constitutive modelling approaches that are embedded in the shell mechanics framework. In this context, two modelling approaches are discussed: cohesive zone and phenomenological damage model. The cohesive zone model is coupled with shell elements to represent the behaviour of thin metal sheets after the onset of localized necking. A calibration method for tension dominated fracture in large plates is discussed, including a separate consideration of weld fracture in aluminium. The phenomenological damage model features a three-invariant plasticity model that accounts for dependence of the strain at fracture on both stress triaxiality and the third invariant of the deviatoric stress. The model is formulated in a shell mechanics framework with explicit enforcement of the plane stress condition for thin sheets. Several application examples are discussed, ranging from controlled laboratory experiments to full scale structural calculations performed in support of the design process.
Danish pastry, coffee and tea will be served 15 minutes before the seminar starts.
All interested persons are invited