Experimental investigation of the influence of integral mechanical attachments on structural behaviour of timber folded surface structures

Abstract

Structural behaviour of timber folded surface systems greatly depends on the connections ability to transfer the occurring forces between the adjacent elements and finally to the supports. This paper focuses on multiple tab-and-slot joints (MTSJ), where digital prefabrication is used to integrate connectors through plate geometry. Multiple plates assembled within a large scale folded surface structure were tested to examine the influence of connection detail type on its global structural behaviour. For this purpose an innovative test setup was devised that approximates uniformly distributed surface load. The connection details used were chosen with respect to preliminary small scale bending tests. Three groups of distinct large scale structures were tested: 1) structures with miter joint detail and adhesive applied along the edges; 2) structures with open slot MTSJ; and 3) structures with closed slot MTSJ. Extensive investigation into the load bearing behaviour and failure propagation for each of the three different types of structures has been conducted.For analysing their feasibility, the tested structures were also reviewed in terms of fabrication time, assembly and on-site construction. The obtained results show that even though adhesively joined structures provide highest structural stiffness, they exhibit multiple disadvantages when considering building scale applications. Open slot MTSJ structures results indicate that these joints cannot provide sufficiently reliable structural behaviour. Structures with MTSJ closed slots show that their joint geometry greatly improves both the ultimate load-bearing capacity as well as stiffness. Furthermore, by transferring the edge occurring forces mainly in compression, they provide additional ductility to the global system. Within the scope of this paper, closed slot MTSJ proved to be a very efficient connection type which can constitute a robust folded structural system made as a multiple assembly of thin timber plates.

Computer Aided Design to Produce High-Detail Models through Low Cost Digital Fabrication for the Conservation of Aerospace Heritage

“…DLP have allowed to manufacture elements in photosensitive resin with very small dimensions at full-scale, being reproduced in the environment of the engineering project. This means a step forward in the detailed representation of engineering projects as opposed to architectural scale models that require geometric simplifications because they cannot be uniformly scaled [3].…”

“…However, this process is not always fast (since the model is not a single piece, and the printing process is not instantaneous). This lack of immediacy is plausible in architecture environments, where reduced scale models are indispensable and geometric simplification processes are required since buildings cannot be uniformly scaled [3].…”

A Calculation Method for Interconnected Timber Elements Using Wood-Wood Connections

“…Until now, most of the research has mainly focused on timber folded plate [7,8] and free-form structures [5,9], which are very specific geometries. As a result, structural analysis has been performed with sophisticated finite element (FE) models [10,11], and the potential resistances of these connections have been mainly studied in rotation, as it is an important parameter for these typologies [12,13].…”

Numerical Simulation of the Semi-Rigid Behaviour of Integrally Attached Timber Folded Surface Structures

“…However, for efficiently realising such structures on building scales, it is essential to provide a pertinent method for their structural analysis. The large scale tests performed by Stitic et al [2] provided insight into timber folded structure behaviour, but only for a certain loading condition and a specific geometry, i.e., vertical loading and anti-prismatic geometry. For different forms as well as varying load combinations, the load paths and load resisting mechanisms will not necessarily be the same.…”

“…The values of occurring plate strains were not addressed. Furthermore, experimental work performed on MTSJ connections [2,8,9] also demonstrated the importance of including semi-rigidity in the numerical models. However, defining the MTSJ connections semi-rigidity by modelling their complete complex geometry has proved to be too cumbersome and computationally expensive to be used on larger scale models with multiple panels [10].…”