Displacement Study of a Large-Scale Freeform Timber Plate Structure Using a Total Station and a Terrestrial Laser Scanner.

Anh Chi Nguyen,Yves Weinand

doi:10.3390/s20020413

Abstract

Recent advances in timber construction have led to the realization of complex timber plate structures assembled with wood-wood connections. Although advanced numerical modelling tools have been developed to perform their structural analysis, limited experimental tests have been carried out on large-scale structures. However, experimental investigations remain necessary to better understand their mechanical behaviour and assess the numerical models developed. In this paper, static loading tests performed on timber plate shells of about 25 m span are reported. Displacements were measured at 16 target positions on the structure using a total station and on its entire bottom surface using a terrestrial laser scanner. Both methods were compared to each other and to a finite element model in which the semi-rigidity of the connections was represented by springs. Total station measurements provided more consistent results than point clouds, which nonetheless allowed the visualization of displacement fields. Results predicted by the model were found to be in good agreement with the measurements compared to a rigid model. The semi-rigid behaviour of the connections was therefore proven to be crucial to precisely predict the behaviour of the structure. Furthermore, large variations were observed between as-built and designed geometries due to the accumulation of fabrication and construction tolerances.

Highlights

Over the past decades, geometrically complex and large-span timber structures have been achieved thanks to advances in both engineering and architecture
Significant research studies have especially focused on the development of timber plate structures using wood-wood connections inspired by traditional carpentry joints
The aim of the present study is to assess the numerical model developed through experimental investigations on large-scale structures and evaluate possible methods to acquire displacements of the loaded structure, using a total station and a terrestrial laser scanner

Summary

Introduction

Geometrically complex and large-span timber structures have been achieved thanks to advances in both engineering and architecture. Significant research studies have especially focused on the development of timber plate structures using wood-wood connections inspired by traditional carpentry joints. These structures consist of a large number of singular planar elements connected at their edges by joints fully integrated in the plates. Research prototypes as well as building-scale assemblies have been built using computer-aided design (CAD) programming and digital fabrication tools [1,2,3,4,5,6]. Mostly based on the finite element method, have been developed for their structural analysis but only limited experimental tests have been carried out on large-scale structures. Experimental investigations remain necessary to better understand their mechanical behaviour and assess the numerical models developed

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