Dissipative joints for CLT shear walls

Abstract (englisch):
Plates or diaphragms made of cross laminated timber are ideal members to transfer vertical as well as horizontal loads in buildings. The excellent mechanical properties of CLT combined with a high degree of prefabrication enable CLT members to be used in residential as well as in other buildings, where steel and concrete are still the predominant building materials. Examples are industrial and commercial buildings, engineered timber structures in general and – in Europe – inner‐city buildings up to about 10 storeys. Earthquake or wind loads on buildings cause diaphragm action in CLT members. CLT members are especially suited for in‐plane loads due to their high shear strength and stiffness. However, the ductility and energy dissipation capacity of a CLT structure is mainly determined by the number and properties of the mechanical connections.

Presently, the required energy dissipation capacity for earthquake loading is often achieved by metallic dowel‐type fasteners loaded beyond their yield load. The load‐slip curves for connections with laterally loaded dowel‐type fasteners show pinched hysteresis loops under cyclic loads. ... mehrAdditionally, the achieved load at a certain displacement decreases
under repeated loading – impairment of strength. Consequently, the connection properties change with the number of load cycles and the energy dissipation capacity decreases significantly. In order to achieve continued energy dissipation under the repeated cycles of a longer earthquake, new steel plate connections were developed and investigated.

For these dissipative shear wall joints the typical pinching and impairment of strength of hysteresis loops at repeated loadings could nearly completely be avoided by arranging
a gap between the CLT members around the steel plate.These steel plate connections are aiming at easy fabrication using automatic processing machines and quick assembly at the construction site. The simple and cost‐effective connection provides high energy dissipation and is easy to design.