Probabilistic Modelling and Model Updating of Tall Timber Buildings : doctoral dissertation

Kurent, Blaž (author), Brank, Boštjan (mentor), Friedman, Noemi (co-mentor), Dolšek, Matjaž (thesis defence commission member), Turk, Goran (thesis defence commission member), Pavic, Aleksandar (thesis defence commission member), Rønnquist, Nils Erik Anders (thesis defence commission member)

Technological advances in engineered timber structural elements have led to an increase in the popularity of mid-rise and high-rise timber buildings. The governing design criterion of such buildings is very often serviceability under wind-induced vibration. Accurate finite element models for predicting their modal properties (i.e. natural frequencies and mode shapes) are crucial for designing buildings that satisfy the current serviceability criteria. It is a challenge for structural engineers to decide what to include in the structural modelling. This is because elements that are typically considered non-structural (partition walls, plasterboards, screed, façade, etc.) have been shown to act structurally and can significantly influence the modal properties of timber buildings. This thesis presents three case studies of timber buildings, where finite element models were developed. Using experimental modal properties, the models were updated to learn about the as-built stiffness characteristics of the analysed buildings. A probabilistic framework based on Bayesian inference was applied to account for the uncertainties. A polynomial chaos expansion was used to develop a surrogate model allowing for a more timeefficient conducting of stochastic analyses such as uncertainty quantification, sensitivity analysis, and Markov chain Monte Carlo posterior sampling. Deterministic and probabilistic approaches were compared and assessed for their effectiveness.

• Language: English
• Keywords: Built Environment, civil engineering, doctoral thesis, timber buildings, wind load, finite element model, modal analysis, surrogate model, model calibration, probabilistic model updating, sensitivity analysis, uncertainty quantification
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [B. Kurent]
• Year: 2023
• Number of pages: XVI, 59 str., [90] str. pril.
• PID: 20.500.12556/RUL-153403
• UDC: 519.22:624.011.1(043.3)
• COBISS.SI-ID: 179283459
• Publication date in RUL: 03.01.2024

Secondary language

• Language: Slovenian
• Title: Verjetnostno modeliranje in posodabljanje modelov visokih lesenih stavb : doktorska disertacija

Abstract

Tehnološki napredek pri lesenih konstrukcijskih elementih je privedel do večje priljubljenosti srednje visokih in visokih lesenih stavb. Vodilni kriterij za projektiranje takih stavb je pogosto uporabna ustreznost stavbe pri vibracijah, ki jih povzroča veter. Natančni modeli končnih elementov za napovedovanje njihovih modalnih lastnosti (t.j. lastne frekvence in oblike) so ključni za projektiranje stavb, ki izpolnjujejo sedanja merila uporabnosti. Gradbeni inženirji morajo sprejeti določene predpostavke o tem, kaj vključiti v konstrukcijsko modeliranje. Izkazalo se je namreč, da elementi, ki običajno veljajo za nekonstrukcijske (predelne stene, mavčne plošče, estrih, fasada idr.), delujejo konstrukcijsko in lahko bistveno vplivajo na modalne lastnosti lesenih stavb. V tej disertaciji so predstavljene tri študije primerov lesenih stavb, za katere so bili razviti modeli končnih elementov. Z uporabo eksperimentalnih modalnih lastnosti so bili modeli posodobljeni, da bi spoznali učinke različnih gradbenih elementov. Uporabljen je bil verjetnostni okvir, zasnovan na Bayesovem sklepanju, z namenom upoštevanja negotovosti v formulaciji. Razvit je bil nadomestni model na podlagi polinomske razširitve kaosa. Ta omogoča časovno učinkovitejše izvajanje stohastičnih analiz, kot so kvantifikacija negotovosti, analiza občutljivosti in vzorčenje posteriorne verjetnosti z Markovsko verigo Monte Carlo. Deterministični in verjetnostni pristop sta bila primerjana in ocenjena glede na njuno uspešnost.

• Keywords: Grajeno okolje, gradbeništvo, disertacije, lesene stavbe, vetrna obtežba, model končnih elementov, modalna analiza, nadomestni model, kalibracija modela, verjetnostno posodabljanje modela, občutljivostna analiza, kvantifikacija negotovosti