Robustness‐oriented topology optimization for steel tubular joints mimicking bamboo structures

Abstract

Steel tubular profiles have outstanding mechanical and architectural performances, but their joints must be manufactured with a vast number of welds and local stiffeners, resulting in complex fabrication and low structural reliability under extreme loads. Fatigue failure is usually a dominant parameter in their design. On the other hand, nature perfectly optimizes its structures with minimized stress concentrations resulting in an extensive fatigue life. In the case of tubular structures, the nodes between the bamboo body and branches are inspiring examples. This article discusses how smarter solutions can be achieved using inspiration from nature by setting the objective of topology optimization to enhance the structural integrity of welded tubular joints between 3‐D‐printed and conventional steel components. Rather than focusing on the “weight reduction,” it prioritizes the objectives of resistance, robustness, and durability. 3‐D metal printing technology, unleashed from the constraints of traditional manufacturing, can enable this structural customization, bringing substantial savings to tubular joint fabrication costs and material waste. To quantify the performance of such joints, the strain energy density method can be the right tool, thanks to its independence on mesh size. This paper provides a review of these subjects and presents brief results of a case study.

Topology Optimisation of Structural Steel with Non-Penalisation SEMDOT: Optimisation, Physical Nonlinear Analysis, and Benchmarking

“…The usage of TO techniques is facilitating the growth of Additive Manufacturing (AM), which can create manufacturable structures from TO results [40]. Moreover, the potential for weight reduction in connections is substantial [41], as is the prospect of developing new connection concepts [42][43][44][45][46].…”

Blended structural optimization for wire-and-arc additively manufactured beams

“…Alternatively, topology optimization algorithms have been implemented to consider the features proper of AM process [19,41]. With reference to the latter, Kanyilmaz et al recently proposed innovative steel tubular joints designed by making use of topology optimization and metal AM techniques by mimicking features present in nature [42]. Recently, a new formulation to implement manufacturing constraints and printing orientation in topology optimization algorithms has been proposed to realize a new generation of WAAM-produced planar elements.…”

Topology Optimisation in Structural Steel Design for Additive Manufacturing

“…As such, the nature-inspired structural concept is particularly prone to TO, in which a solution for optimising and manufacturing its joints is paramount. Other interesting developments in the TO of joints among tubular elements can be found in the work by Kanyilmaz and Berto [429,430]. Concerning the optimisation of spherical nodes in space frames, the work by Hassani et al [364] is particularly relevant for providing a holistic guideline, including fabrication concerns, practical issues with Grasshopper modelling, as well as results post-processing and interpretation.…”