Behaviour of various framed timber joints: Capacity and improved design rules

• Published in: Journal of Building Engineering 2021-12, Vol.44, p.103417, Article 103417
• Main Authors: Aejaz, S.A., Dar, M. Adil, Dar, A.R., Bhat, J.A., Carvalho, Hermes
• Format: Article
• Language: English
• Subjects: Finite element analysis; Shear bearing failure; Tensile resistance; Timber joints
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2021.103417

Unlike conventional building materials like concrete, steel, aluminium, etc., timber offers a sustainable alternative due to its economy and energy efficiency and lesser carbon footprint. However, timber-framed structures possess joints as the most vulnerable elements despite their remarkable seismic resistance, having high damage susceptibility. Past studies on timber frames have mainly stressed the frame behaviour with a specific joint profile rather than the performance of various joint forms, commonly employed in timber construction. Additionally, studies to refine the joint details by optimizing the same are minimal. Thus, in the present research, using the results from the tests performed earlier on different joints (in terms of joint profile, nailed only, and nailed and with adhesive), the experimental data was used to model the observed behaviour numerically in ABAQUS. The FE models were validated and subsequently used in conducting parametric studies to obtain data over a broader domain to evaluate the effect of geometrical modifications on the joint behaviour. This facilitated in obtaining optimal joint profiles and helped in bringing out various recommendations on the same. Moreover, the numerical peak load values were compared against the design strengths evaluated using National Design Specifications (NDS)-2018 guidelines to ascertain the prediction accuracy. This comparison revealed that the predicted joint strengths varied from being unconservative to being extremely over-conservative. Thus, to improve the strength prediction using NDS-2018 guidelines, modification factors were brought out. •Different types of framed joints for sustainable and cleaner structures are studied.•Peak strength, load-displacement response and stress distribution are studied.•Extensive parametric studies carried out to bring out optimal joint dimensions.•Modification factors are proposed inNDS-2018 for more accurate predictions.