166 S.A. Smith et al. Table 15.8 Mac for all regular bolt model vs original model Original bold model All regular bold model Mode 1 2 3 4 5 6 7 8 9101112131415 1 80:7 18:7 0:6 0 0 0:2 0:1 0 0:2 0:2 0:1 0:9 0:2 0 0:1 2 18:6 80:5 0 1:3 0 0:1 0 0 0:6 0:4 0:2 0:2 1:1 0 0:1 3 0:3 0 99:5 0:1 0 0:5 0:2 0 0:1 0:3 0 0:2 0:1 0 0:1 4 0:1 0:5 0:1 99 00:40:800000000 5 0 0 0 0 100 0 0 0:10:80 0:80:10:10 0 6 0:30 0:80:2 0 98 1:70:20 0 0 0 0 0 0 7 0 0:1 0:1 1:2 0 2:1 97:7 0:5 0 0 0 0 0 0:1 0 8 0 0 0:1 0 0:1 0 0:2 99:6 0:1 0 0 0 0 1:3 0 9 0:1 0:5 0:1 0 0:9 0 0 0:1 90:8 7:9 1:6 0 0 0 0:2 10 0:6 0:2 0:2 0 0:2 0 0 0 4:891:3 3 0:1 0 0 0 11 0 0:7 0 0:1 0:6 0 0 0:1 2:6 1:9 94 1:1 0 0 0:2 12 1 0:2 0:2 0:1 0:1 0 0 0 0:1 0:8 0:1 6:6 92:8 0 0 13 0:2 0:6 0:1 0 0:1 0 0 0 1:1 0:2 2:8 90:8 7:3 0 0:3 14 0 0 0 0 0 0 0 1:40:10 0 0 0 99:90:1 15 0:2 0:1 0:1 0 0 0 0 0 0:1 0:2 0 0:3 0:4 0:1 57 Fig. 15.15 FE model of the assembled tower as flexible boundaries by modeling it as sets of springs [17, 29]; however this simplification causes errors in the structure at resonance [17]. Modeling the soil as a continuum using linear elastic elements could be used to avoid the source of the resonance error [17, 29]. Due to soil having a porous structure the mass and stiffness must take into account, the mass of the soil and water, the stiffness of the soil skeletal structure, as well as the forces associated with the fluid; these parameters result in a complex, damped, coupled equations of motion [30]. The soil substructure is assumed to be “Drained, Saturated Porous without Phase Change” which assumes that the liquid pressure does not change with time resulting in linear equations of motion. The boundary is modeled with the concrete pad the tower is built on and the soil surrounding the pad; the model containing the solid continuum can be seen in Fig. 15.17. The soil is modeled using a 200m cubic continuum with fixed boundaries;
RkJQdWJsaXNoZXIy MTMzNzEzMQ==