Analysis of combined cable‐guided retractable membrane structures with highly detailed global FEM‐models

Abstract

Cable‐guided retractable membrane structures represent lightweight systems combining adaptability to environmental conditions and multifunctional use of large‐span spaces. While these structures offer material efficiency, structural flexibility, and aesthetic integration across diverse applications, there is a complex correlation of the static and dynamic behavior between the retractable structure and their adjacent structural components.

The new membrane structure for the amphitheater at Lake Czos in Mrągowo, Poland, exemplifies this interaction. The structure integrates two stationary and two independent retractable membranes with a large steel arch, spanning 65 m and covering a total area of approx. 4000 m ² with 5100 seats. Eight main suspension cables serve a dual function: they carry the lower stationary membrane surfaces while simultaneously acting as guiding cables for the upper retractable membranes. This combination of functionalities creates a significant interdependence between the two systems, which might otherwise be perceived as independent. To obtain reliable forces and results for the dimensioning and design of all structural and driving components, it was essential to develop a comprehensive FEM analysis model including all membranes, cables, hangers and carriages.

This paper discusses the specific characteristics and challenges of the referred project and their integration into the development of a global FEM analysis model. The focus is placed on the geometric complexity of the retractable membranes and its implications for the drive system, as well as the detailing of not only the retractable components itself.