Detailed and simplified non-linear models for timber-framed masonry structures

Abstract

This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent repository link AbstractThe need for improved methodologies to describe the post-elastic behaviour of existing structures in the framework of seismic vulnerability assessment has long been recognised. The study presented herein deals with the non-linear seismic response of timber-framed (T-F) masonry structures, such as those found in traditional edifices of cultural heritage. T-F masonry generally consists of masonry walls reinforced with timber elements, including horizontal and vertical elements, as well as X-type diagonal braces. Since the Bronze Age T-F buildings were common in regions where moderate to strong earthquakes were frequent. There is ample historical evidence that the embodiment of timber elements in masonry walls is closely related to earthquakes. The paper focuses on the description of the seismic response of T-F structures by means of a detailed analytical model. Although elastic analysis can adequately identify regions with high stresses, it fails to capture the redistribution of stresses and the ensuing failure mechanism. The simulation of T-F 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 *Manuscript

Derivation of Fragility Curves for Traditional Timer-Framed Masonry Buildings Using Nonlinear Static Analysis

“…The configuration of the diagonals of the TFM is not exactly known due to the presence of the opaque metal sheathing. It is assumed here that every TFM panel consists of two diagonals as illustrated in Figure 3b, and a previously developed model for TFM with two diagonal braces [8] is utilised. The timber frame of the upper storeys is supported by both the ground floor URM and the timber posts of the secondary system shown in Figure 3.…”

“…TF walls are modelled by axial force vs. axial deformation (N-ε) lumped plasticity hinges in the diagonals [8]. Modification of the axial stiffness of the diagonals is required to take into account their sliding:…”

Fragility Curves and Loss Estimation for Traditional Timber-Framed Masonry Buildings in Lefkas, Greece

“…This is attributed to the inclusion of the masonry infills in their model and the difference in the total height. This elastic model with natural period equal to 0.19 s has two diagonals active in each panel; however, this linear elastic response is very short and for a broader displacement range of the response only the diagonal in compression will be active (Kouris and Kappos 2012). For a linear model with elastic modulus E and two diagonals with section area A and lengths in compression L c and in tension L t , respectively, the equivalent modulus of elasticity E' for the frame with only compression diagonals can be found as follows:…”

“…The yield and failure surfaces are presented in Figure 6. Details about the micro-model can be found in Kouris and Kappos (2012).…”

“…A macro-model technique is adopted (Kouris and Kappos 2014) based on lumped plasticity point hinges in the strut elements. This model has been based on the micro plasticity model of Kouris and Kappos (2012). However, the computational effort to derive reliable results for entire buildings is the major drawback of the micro-model that limits its applicability.…”