Phd thesis of GOMEZ LLACTAHUAMANI Dalmer

Summary : 

The construction of tall wooden buildings has been increasing in recent years. This type of building uses different construction methods depending on the elements used but also depending on the resumption of stress. These methods involve the use of assemblies to transmit forces. Wooden constructions face challenges due to limited knowledge of phenomena such as fires, vibration behavior, impact of humidity, durability, load transmission through assemblies, creep, etc. This thesis is more particularly linked to vibration behavior with a focus on the behavior of the assembly under variable load.

To evaluate nonlinearities in the assembly, quasi-static loading tests are conducted at several levels, camera measurements are used (DIC). The static behavior of the assembly depends on several factors linked to the wood at the stem and to the contact. For these assemblies, a nonlinearity is clearly observed with hysteresis under cyclic loading. For static behavior, a model using finite elements can predict the behavior of the assembly as well as evaluate the level of plasticization of the pins and wood. For behavior under cyclic load, phenomenological models are capable of reflecting hysteresis. The complexity of these models is the number of parameters required. Another source of complexity is the variability, they are of material origin due to the anisotropy of the wood but also to geometric configurations which reveal hyperatticisms in the assembly. Phenomenological models of cyclic behavior are often used to predict the dynamic behavior of the assembly. A differential formulation of the force displacement curve of the assembly is then necessary. This last point is currently being developed to adapt the model to the Kalman filter for dynamics.

Supervision :

Under supervision of Pr. Nicolas PEYRET (Isae-Supméca), Gwendal CUMUNEL (ENPC, Laboratoire Navier), Thomas CATTEROU (FCBA) and Michel BORNERT (ENPC).