Design of Beam Ends with Copes
Coping of beams is usually done in order to allow for clearance at connections, but doing so reduces the beams strength and makes it susceptible to local web buckling at the coped section. Due to this reduction of the beam's strength, it was of interest to reinforce the web at the coped end. Previous researchers have proposed several design recommendations for reinforcement of coped beams. Possible measures involves welding on endplates or use of bolted connections at the coped end, and provision of stiffeners at the coped region.
In this thesis a numerical study on the coped beam's strength and behaviour is presented. Nonlinear finite element analyses have been conducted to predict the structural behaviour and capacities of coped beams with varying cope dimensions. The beam was strengthened by either restraining the coped end from lateral translation or by provision of stiffeners at the coped region.
The effect of restraining the coped end depended on the cope dimensions. For cope length-to-reduced beam hight ratios lesser than 1 (c/h_0 < 1), restrainment of the coped end would successfully increase the beams capacity. For ratios equal to or more than one (c/h_0 >= 1), the effect was negligible.
Reinforcement in longitudinal direction only did not prevent the occurence of local web buckling, so that the recommended reinforcement details of the coped beam included a combination of stiffeners in both vertical and longitudinal direction for which the beam was able to develop the plastic moment capacity of the full beam section without any significant sideways rigid body movement of the longitudinal stiffeners. The proposed design recommendations considers the webs slenderness and coped dimensions.
For coped beams with web depth-to-thickness ratios (h_w/t_w) less than or equal to 58 and cope length-to-reduced web hight ratios (c/h_0) less than one, longitudinal and vertical stiffeners were required while double vertical stiffeners were required for cope ratios equal to or more than 1. For coped beams with web depth-to-thickness ratio more than 58 and less than or equal to 67 and cope ratios less than or equal to 0.5 vertical and longitudinal stiffeners were required, while double vertical stiffeners were required for cope ratios of more than 0.5.
Place, publisher, year, edition, pages
Institutt for konstruksjonsteknikk , 2013. , 130 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-22652Local ID: ntnudaim:9777OAI: oai:DiVA.org:ntnu-22652DiVA: diva2:651202
Aalberg, Arne, FørsteamanuensisLarsen, Per Kristian