This paper presents a discussion of salient issues surrounding the modeling and performance of bolted connections in wood construction. To understand the complex behavior of bolted joints under a load, a number of key issues related to connection geometry, material, and mechanics need to be understood. Issues addressed in this paper include the design philosophy of bolted joints (allowable stress and reliability-based design), the influence of connection geometry on behavior under load, and a discussion of previous models that have been used to predict connection performance. Discussions of the key models used to predict connection load behavior, including the European yield model, which currently serves as the basis for allowable connection load in U.S. codes, and various failure criteria are presented. Of particular interest is the discussion of the strengths and weaknesses of the two-dimensional (2D) models that have been used historically to quantify connection behavior. These are seen relative to developments in three-dimensional (3D) modeling of bolted connections. The contributions of modeling pin/wood contact surfaces to connection behavior prediction are also considered.

Modeling bolted connections in wood: review

Quasi-static mechanical behaviour of a double-shear single dowel wood connection

The purpose of this paper is to provide a comparison between embedding tests covered by the EN383 and ASTM D5764 standards, highlighting some difficulties regarding the application of the referred standards. These embedding tests are essential to evaluate the embedding strength of wood, which is required for the assessment of joints strength. The proposed comparison is based either on experimental data and numerical simulations through the finite element (FE) method. Tests were performed on maritime pine wood (Pinus pinaster Ait. species) according to the longitudinal and radial directions, allowing the comparison of the embedding strength and elastic foundation modulus. Three dimensional FE models of the tests were built using contact elements technology and assuming the steel dowel and wood as linear elastic isotropic and orthotropic materials, respectively. The contact modelling is a challenging topic for which this paper also proposes some guidance. The test configuration proposed in the EN383 standard for assessment of the embedment strength in compression is more susceptible to the dowel bending than the half-hole test configuration proposed in the ASTM D5764 standard. The numerical simulation of the EN383 embedding test raises some additional difficulties regarding the dowel boundary conditions.

A Comparison Between the EN 383 and ASTM D5764 Test Methods for Dowel‐Bearing Strength Assessment of Wood: Experimental and Numerical Investigations

A mechanistic model is presented for predicting the tensile stiffness and strength of 2 by 4 lumber boards containing a single major face knot. The primary inputs to the model are local grain angle maps for each wide face of a board and estimates of average clear-wood properties. The grain angle maps were obtained through electrical scanning of board surfaces and represented the in-plane orientation of the wood fibers. Out-of-plane dive angles were not considered. The model simulates the failure process that occurs within lumber subject to tension and thereby provides insight to, and understanding of, the failure of wood with defects. The model is devoid of empirical adjustment factors, and it has produced tensile strength predictions that correlate with measured strengths by a correlation coefficient of 0.86 and an average absolute error of 12%. It is hoped that insight gained through use of this model will provide a foundation for improvements in lumber grading.

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Predicting lumber tensile stiffness and strength with local grain angle measurements and failure analysis

Probability-based LRFD for engineered wood construction

Timber is an abundant and renewable natural resource and its use exceeds all other construction material. Structural wood represents a challenge of vast dimensions and attention to various research topics on structural wood is needed. The papers in this publication define these areas of research needs. A state-of-the-art review is presented. Short and long term needs and priorities are identified. Places where research is conducted and sources of potential support are also identified. Specific subjects discussed include: Structural material—lumber; connections; subassemblies such as walls and floors; heavy timber structures and bridges; structural materials—panels; reliability based design; trusses and manufactured structural components; and light frame buildings.

Structural Wood Research: State-Of-The-Art and Research Needs

Structural wood research : state-of-the-art and research needs : proceedings of the workshop held at the Marc Plaza Hotel, Milwaukee, Wisconsin, October 5 and 6, 1983

Rafik Y. Itani

Papers

Structural Wood Research: State-Of-The-Art and Research Needs

Structural wood research : state-of-the-art and research needs : proceedings of the workshop held at the Marc Plaza Hotel, Milwaukee, Wisconsin, October 5 and 6, 1983