Analysis and Calculation of Stability Coefficients of Cross-Laminated Timber Axial Compression Member

Bedon

Fragiacomo

2022

Preprint

This paper investigates the column buckling behaviour of three-layer Cross Laminated Timber (CLT) panels under compression, from both the experimental and numerical point of view. The main aim of present study is hence to define the expected load-bearing capacity for these composite CLT solutions, and to assess the typical fracture mechanism for two different series of specimens of possible technical interest for construction applications. To this aim, a total of 14 column buckling experiments is carried out. First, a set of 7 homogeneous speciemens (“HO” series), which are entirely made of beech, are investigated. Their load-bearing capacity is compared with the column buckling performance of 7 hybrid specimens (“HB” series), whose inner layers are made of Corsican pine. Overall, the experimental analysis gives evidence of a rather stable column buckling capacity for CLT panels, with evidence of major failure mode due to out-of-plane bending phenomenam, but also rolling shear and delamination. Finally, further assessment of experimental evidences is provided by extended analytical calculations (based on existing formulations, including the Eurocode 5 approach) and even Finite Element (FE) numerical analyses for the examined three-layer CLT compositions. Comparative results are discussed in terms of structural performance, capacity, weakness of analytical models for CLT solutions.

Section: ) Column Buckling and Stability Issues For Clt Panelsmentioning

confidence: 99%

Experimental and numerical column buckling analysis of hardwood Cross Laminate Timber (CLT) panels

Bedon

Fragiacomo

2022

Preprint

“…In this framework, native hardwoods species such as beech which is extensively available in European forests [13] proved to have relevant mechanical features for CLT structural applications [14]. Many researches have been also conducted to better understand the CLT behavior under different load conditions as bending [15], compression [16,17], and shear [18,19], nevertheless the CLT in-plane behavior under compressive loads, leading to column buckling is currently poorly investigated as for softwood [20,21] as for hardwood species. For timber structural components and systems, stability issues have a critical role in design procedures, due to the challenging trend of modern applications towards the construction of high-rise timber buildings as well for the intrinsic material's nature.…”

Section: Introduction 567mentioning

confidence: 99%

“…CLT members, depending on the boundary conditions, can be addressed as: i) one-way elements if they are restrained on two opposite sides; or as ii) two-way elements if them are constrained on three or all sides. Few studies that have addressed the buckling behavior of CLT members considered them as one-way elements [22]. Some researchers have been carried by performing experimental tests; [23] investigated the axial compression behavior of both cross-laminated timber columns (CLTCs) and control glued-laminated timber columns (GLTCs).…”

Section: Introduction 567mentioning

confidence: 99%

Buckling Analyses of Cross Laminated Timber Panels

World Conference on Timber Engineering (WCTE 2023)

Santis

Bedon

et al. 2023

This paper investigates the column buckling behaviour of three-layer Cross Laminated Timber (CLT) panels under compression, from both the experimental and numerical point of view. The main aim of present study is hence to define the expected load-bearing capacity for these composite CLT solutions, and to assess the typical fracture mechanism for two different series of specimens of possible technical interest for construction applications. To this aim, a total of 14 column buckling experiments is carried out. First, a set of 7 homogeneous specimens ("HO" series), which are entirely made of beech, are investigated. Their load-bearing capacity is compared with the column buckling performance of 7 hybrid specimens ("HB" series), whose inner layers are made of Corsican pine. Overall, the experimental analysis gives evidence of a rather stable column buckling capacity for CLT panels, with evidence of major failure mode due to out-of-plane bending phenomena, but also rolling shear and delamination. Finally, further assessment of experimental evidence is provided by extended analytical calculations (based on existing formulations, including the Eurocode 5 approach). Comparative results are discussed in terms of structural performance, capacity, weakness of analytical models for CLT solutions.

Experimental investigation and beam-theory-based analytical model of cross-laminated timber panels buckling behavior

Fabrizio

Spera

et al. 2023

Archiv.Civ.Mech.Eng

This paper investigates the buckling behavior of three-layered cross-laminated timber (CLT) panels, from both the experimental and analytical standpoints. Two different series of specimens are considered: the homogeneous ones, which are entirely made of beech, and the hybrid ones, whose inner layers are made of Corsican pine. The experimental tests aim to evaluate the failure limit loads of the specimens, when loaded by an increasing compression tip force. The analytical formulation is first obtained for a panel with a generic number of layers and after it is specialized for a three-layered panel. Timber layers are modeled as internally constrained planar Timoshenko beams linked together by adhesive layers, which are modeled as a continuous distribution of normal and tangential elastic springs. A closed-form solution of the buckling problem is obtained. The achieved Eulerian critical load of CLT panels depends on two parameters, which account for (1) the interaction between timber layers (due to the glue tangential stiffness) and (2) the rolling shear stiffness of the inner layer. Three different failure criteria are introduced to estimate the limit load. Finally, the analytical limit loads and the experimental ones are compared.