Issue 45

F. Brandão et alii, Frattura ed Integrità Strutturale, 45 (2018) 14-32; DOI: 10.3221/IGF-ESIS.45.02 19 The church dates back from the beginning of the 19 th century and was built in a place where there was a small niche in the old Rio street, near the Acaraú River [27]. This church is very close to the Igreja da Sé of Sobral, and next to the urbaniza- tion of the near left of the Acaraú River. Its structure is composed of clay bricks masonry, and the church was built using local constructive techniques. The church’s geometry, shown in Fig. 5, is almost regular with a length of about 26.2 m and a width of about 11.9 m; there is a lateral tower 20.50 m high. The structure is divided in a Central Nave (about 6.5 m  16.0 m) and in a Lateral Nave (about 3.2 m  12.0 m), separated by two columns and three arches. The Coro-Alto, the Al- tar-Mor and an office are located at the end of the building (Fig. 5). Finite element modeling Based on a geometric survey, provided by IPHAN-CE, and on the geometric characteristics observed by visual inspection, a 3D numerical model of the Nossa Senhora das Dores Church was built (Fig. 6). To build the 3D FE model some sim- plifications were done, aimed to reduce possible discontinuities in the finite element mesh. The architectural details of the main façade, the reinforced-concrete (RC) stair, the roofs and the Coro-Alto were not included in the model, but their re- spective loads and masses were applied on the corresponding walls. The FE model was built with the commercial code ANSYS; SOLID187 tetrahedral elements with quadratic displacement behavior were employed (the finite element is defined by 10 nodes having three degrees of freedom at each node). A mesh-size of about 500 mm was adopted and the final FE model, shown in Fig. 6, was built with 53,889 elements and 93,380 nodes. Figure 6 : View of the 3D finite element numerical model of the Nossa Senhora das Dores Church. With respect to the loads and weights of the structural elements, the following assumptions have been made. The stair loading was assumed, according to [28], equal to 2.50 kN/m 2 ; this load was assumed uniformly distributed at the top sur- face of the four tower walls. To evaluate the Coro-Alto load, a timber type Pine was considered with specific weigh equal to 5.0 kN/m 3 . Taking into account the geometric dimensions of the Coro-Alto, its corresponding load is equal to 1.25 kN/m 2 . The roof is a timber structure where the ceiling tiles are supported. At the intrados of the roof, a ceiling plaster - as usually adopted in the Sobral region - is fixed at the timber structure. For the ceiling plaster a loading value of 0.60 kN/m 2 was adopted, the same adopted by [29]. For the roof load, a load of 1.30 kN/m 2 , the same adopted in [30], was used. This leads to a total load of 1.90 kN/m 2 . Considering an additional extra-load of 50% of the total load (0.95 kN/m 2 ), the total load of the roof was equal to 2.85 kN/m 2 . The roof load was distributed along of the walls that support the roofs element. The final applied loads in the numerical simulations are summarized in Tab. 1. Stair (kN/m 2 ) Coro-Alto (kN/m 2 ) Roof (kN/m 2 ) 2.50 1.25 2.85 Table 1 : Loads applied in the 3D numerical model E (GPa) W (kN/m 3 ) f c (MPa) f t (MPa) ν 1.50 18.00 3.20 0.16 0.20 Table 2 : Preliminary mechanical properties of the numerical model