Modeling of the Beam-To-Column Dowel Connection for a Single-Story RC Precast Building

As widely known, connections performance under seismic loads can significantly affect the structural response of RC precast buildings. Within the scientific community, an increasing number of studies has been carried out on this topic, in the light of the recent earthquake aftermaths all over Europe. Indeed, connections turned out to be the weakest part of the precast structures and their failure often provoked the global collapse of the whole building. The present study aims at assessing the seismic behavior of a single-story RC precast building in terms of global collapse implementing two different models of the beam-to-column connection, a simplified and a refined one. A lumped plasticity approach is used to simulate the structural nonlinear behavior at the column base. In order to assess the refined connection model, a preliminary scheme with an isolated single dowel is validated by comparing the pushover outcomes with experimental results from literature. Nonlinear static and dynamic analyses are performed on two models of a 3D single-story RC precast building, one implementing the simple beam-to-column connection model and the other one implementing the refined mode. The comparison clearly shows that the differences are negligible if the global collapse limit state is considered.

Behavior of Timber-Steel Composite with Dowel Connection under Fire

Recently, a hybrid structure called Timber-Steel Composite (TSC), which is assembled by a central steel I beam with wooden block covered, is expected to introduce a potential strength for the design of modern wooden structure. However, information on this type of structure under the influence of fire is not yet sufficiently explicit to provide designers with a reliable index. The aim of this research was to study the behavior of TSC with dowel connection under fire. Three TSC with bolt connected were tested and were burnt under temperature 700 °C within 10 minutes. Testing results showed that after 10-minute fire burning, the temperature of central I beam is not of great increased, indicating that the wooden block help transmits heat although the dowel connections which connect steel and wood is directly exposed to the fire. It is also observed that dowel connection and air gaps caused a relatively high percentage of char for the wood surrounding the bolt as 13% of total area. In conclusion, a useful prediction on char depth no more than 5cm could be estimated for 1-hour testing validating the purpose of applying TSC in future.

Load-Carrying Behaviour of Dowel-Type Timber Connections with Multiple Slotted-in Steel Plates

The multiple-shear dowel connection with slotted-in steel plates is one of the most efficient joints for large cross section timber structures. Experiments were performed on dowel-type timber connections with one, two and three slotted in steel plates under lateral loads parallel to the grain. Test variables include the number of steel plates, the spacing of the steel plates, and the dowel diameter. Results show that the load-carrying capacity of the dowel-type connection increased as the number and spacing of steel plates in the same thickness of timber specimens. Finally, a model of the load-carrying capacity of multiple shear steel-to-timber connections is presented, which showed good agreement with the results obtained in the experiment.