This page contains automatically translated content.
Research colloquium: Lecture by Tarun Mitruka, M.Sc., and Dr.-Ing-Simon Bieber on the Mixed Displacement Method
We cordially invite you to the first lecture as part of the research colloquium for final theses, and doctoral as well as habiliation candidates n the coming year 2026. This will take place on Tuesday, 13.01.2026 at 16:30 in room 3516 (Mönchebergstr. 7). We are pleased to have Mr. Tarun Mitruka, M.Sc. (University of Stuttgart) and Dr.-Ing. Simon Bieber (formerly University of Stuttgart; DYWIDAG International GmbH Leipzig) as guest lecturers. The title of the lecture is:
"The Mixed Displacement Method: A Variational Approach to Intrinsically Alleviate Locking"
Welook forward to seeing you there.
Abstract
Locking is a well-known problem in the context of the finite element method (FEM). While the locking phenomenon itself is characterized by poor coarse-mesh accuracy with underestimated displacements and oscillating stress components in dependence of a certain parameter, there exist different types of locking. Typical examples are shear locking (in-plane and transverse), membrane locking, trapezoidal locking, volumetric locking, etc. While many solution strategies have been developed to alleviate the problem of locking within the framework of FEM, with newly evolving discretization methods, like meshless methods, isogeometric analysis, scaled boundary FEM, virtual element methods, etc., the necessity to create or extend the already developed methods reemerges. To circumvent this task, the mixed displacement (MD) method was designed. As the name suggests, it is a mixed method, where additional degrees of freedom are added that adhere to a carefully chosen kinematic law. This kinematic law is constructed such that the formulation is intrinsically locking-free, i.e., it is locking-free independent of the discretization method. In spite of its simplicity, the MD method carries the challenge of handling certain additional constraints that are to be imposed on the additional degrees of freedom.
In this work, an overview of the MD method is presented, and recent developments are discussed. Numerical examples showcasing the transverse shear locking-free characteristics in straight beams and plates, membrane locking-free properties in curved beams and shells, in-plane shear locking, and volumetric locking-free attributes in 2D solids will be demonstrated. The examples will cover both geometrically linear and nonlinear examples within the framework of standard FEM and isogeometric analysis.