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Reconan FEA v2.00 software manual.
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... Femap pre-processing software does not provide the user with the necessary tools for entering custom made properties regarding several features of the FE models (like the number of fibers per control section in the case of the NBCFB element), the SMAD Custom properties software ( Fig. 7.1) was used for providing any additional parameters required by the ReConAn solver for the assemblage and solution of the numerical problem at hand. The SMAD Custom properties software was developed by G. Stavroulakis during his Ph.D. Thesis, which deals with soil-structure interaction problems under seismic loading with the use of the ...
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... chapter presents the ability of ReConAn to model 3D structures and combine the two different beam finite elements incorporated in its FE library. To serve this purpose, the 2-storey 3D frame is considered (Fig. 7.1) for nonlinear analysis according to the EC8 [3] . For simplicity reasons the distributed loads will be accounted for as concentrated gravity forces applied at the structure's beams. In addition to that, the direction that will be investigated is only the global x-axis which is the direction where the horizontal loads will be applied. ...
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... gravity forces applied at the structure's beams. In addition to that, the direction that will be investigated is only the global x-axis which is the direction where the horizontal loads will be applied. Therefore, the next step is to compute the horizontal loads, and then construct the FE mesh according to the idealized model shown in Fig. 7.1. The procedure of constructing the mesh will be also presented in detail so as to illustrate the way that ReConAn accounts for different modeling feature (i.e. diaphragm, offsets, static dead loads, etc.). ...
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... first step is to create three properties named "Column30x30", "Beam30x60" and "ShearWall30x150", through the Model → Property command. Then assign the custom properties to each property according to the material features and the reinforcement details ( Fig. 7.3). As it was illustrated, the SMAD custom property "Beam Fiber" only foresees a single diameter for the cases of the stirrups and longitudinal rebars. As it can be seen in Fig. 7.3, for the case of the column section ( Fig. 7.2) the selected stirrup diameter is 17mm instead of 12mm. This is performed after computing the equivalent ...
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... through the Model → Property command. Then assign the custom properties to each property according to the material features and the reinforcement details ( Fig. 7.3). As it was illustrated, the SMAD custom property "Beam Fiber" only foresees a single diameter for the cases of the stirrups and longitudinal rebars. As it can be seen in Fig. 7.3, for the case of the column section ( Fig. 7.2) the selected stirrup diameter is 17mm instead of 12mm. This is performed after computing the equivalent diameter of the stirrup that derives from the geometry used to reinforce the section of the column. The diameter of the stirrups is 12mm and 3 hoops are placed, which create a grid of ...
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... Then assign the custom properties to each property according to the material features and the reinforcement details ( Fig. 7.3). As it was illustrated, the SMAD custom property "Beam Fiber" only foresees a single diameter for the cases of the stirrups and longitudinal rebars. As it can be seen in Fig. 7.3, for the case of the column section ( Fig. 7.2) the selected stirrup diameter is 17mm instead of 12mm. This is performed after computing the equivalent diameter of the stirrup that derives from the geometry used to reinforce the section of the column. The diameter of the stirrups is 12mm and 3 hoops are placed, which create a grid of four rebars at each direction. Therefore, after ...
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... located along the global x-axis, is constructed through the use of rigid elements, its actual length is 4.0m, while if the end nodes of the shear wall and the column are used the corresponding length is 4.9m (4.0m + 0.75m + 0.15m). It is obvious that the second frame has a larger span thus its resistance to horizontal in-plane loading is smaller. Fig. 7.5 shows the FE mesh of the first storey of the RC structure. As it can be seen, the exact geometry of the frame is discretized through the use of rigid elements while the diaphragmatic behavior that the slab induces due to the corresponding assumption, is also discretized through the X-type rigid elements shown in the right model of ...
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... Fig. 7.5 shows the FE mesh of the first storey of the RC structure. As it can be seen, the exact geometry of the frame is discretized through the use of rigid elements while the diaphragmatic behavior that the slab induces due to the corresponding assumption, is also discretized through the X-type rigid elements shown in the right model of Fig. 7.5. The beams are discretized with four finite elements per structural member (Fig. 7.5 Left model). It is noteworthy to point out at this stage that this type of models must not contain any coincident nodes, a result of the copy / past element procedure. The command Tools → Check → Coincident Nodes has to be always executed at the end ...
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... be seen, the exact geometry of the frame is discretized through the use of rigid elements while the diaphragmatic behavior that the slab induces due to the corresponding assumption, is also discretized through the X-type rigid elements shown in the right model of Fig. 7.5. The beams are discretized with four finite elements per structural member (Fig. 7.5 Left model). It is noteworthy to point out at this stage that this type of models must not contain any coincident nodes, a result of the copy / past element procedure. The command Tools → Check → Coincident Nodes has to be always executed at the end of each copy / past command or at the end of the FE mesh generation. Moreover, if ...
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... along the X, Y and Z axis has to be performed, especially for the case of large scale FE meshes. This procedure will minimize the required storage allocation size for the stiffness. If the user does not want to perform the renumbering procedure for all the global directions, then at least one renumbering has to be performed along any direction. Fig. 7.6 shows the FE mesh after the copy / past command executed so as to reproduce the 2 nd storey of the structure. The users have to be extremely caution when reproducing the 2 nd storey given the fact that the two floors have different heights. In order to uplift the this geometrical problem, the length of the first finite elements is ...
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... command executed so as to reproduce the 2 nd storey of the structure. The users have to be extremely caution when reproducing the 2 nd storey given the fact that the two floors have different heights. In order to uplift the this geometrical problem, the length of the first finite elements is modified, which is also visible in the model shown in Fig. 7.6. ...
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... assigning any nodal constraints the Model → Constraint → Create/Manage Set command has to be executed so as to create a new constraint set. Then, as it was described in Section 5.3, the four nodes of the model's base are selected and fixed. The resulted model can be seen in Fig. 7.7. ...
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... nonlinear solution procedure. For uplifting this numerical problem, ReConAn has incorporated a command that is activated according to the load set's name. If the user wants to apply these loads at the first load step linearly, the name of this load set has to be set to "LoadStatic". Then apply the concentrated loads as illustrated in Section 5.4. Fig. 7.8 shows the procedure needed to be executed so as to create a load set named "LoadStatic". The first action that needs to be performed after the creation of the load set "LoadStatic", is the execution of the command "Body" in order to activate the body loads that result due to gravity. Fig. 7.9 shows the "Create Body Loads" window ...
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... the total load per slab due to the distributed load sets according to the seismic load combination is 61.88 + 0.3 x 74.25 = 84.16 kN. The corresponding weight of each slab is equal to 4.5 x 5.5 x 0.2 x 24.72 = 14.94 kN thus the total vertical load that will be distributed to the four beams located at each storey equals to 84.16 + 14.94 = 99.10 kN (Fig. 7.10). ...
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... final step is to create the load set that will be used to impose the horizontal nonlinear seismic loads, which were computed in Section 7.1, and define the nonlinear parameters of the solution procedure (Fig. 7.11). The horizontal loads are distributed equally at the two end nodes of the structural beams of each storey, as it is illustrated in Fig. 7.12. ...
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... final step is to create the load set that will be used to impose the horizontal nonlinear seismic loads, which were computed in Section 7.1, and define the nonlinear parameters of the solution procedure (Fig. 7.11). The horizontal loads are distributed equally at the two end nodes of the structural beams of each storey, as it is illustrated in Fig. 7.12. ...
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... it can be seen in Fig. 7.11, a total number of 25 load increments was defined, which is the number of load steps that the nonlinear static load will be imposed during the solution procedure. After exporting the neutral file according to the guidelines given in Section 5.6, the ReConAn application file is executed and the analysis is performed. 7.13 shows the ...
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... exporting the neutral file according to the guidelines given in Section 5.6, the ReConAn application file is executed and the analysis is performed. 7.13 shows the resulted deformed shape of the RC frame as it was predicted by the nonlinear solver. ...
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... nonlinear solver. As it can be seen, the maximum computed displacement due to the horizontal seismic loads was 3.93 mm which shows that the load computed according to EC8 is carried with safety from the frame of the structure. Practically this numerical result can be interpreted as over design of the structure's frame. This is also illustrated in Fig. 7.14, where a failure analysis is presented in the form of a P-δ curve, which derived after the increase of the horizontal loads. The computed failure load was 1678 kN which is more than 8 times larger than the horizontal loads computed according to the EC8 provisions. Having an one span 3D frame which has relatively small mass, the ...
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... this action is not performed, then Femap will show the results imported during the last import that was performed according to this rule and not the newly imported numerical results. Figure 7.14 P-δ curves for 25 and 50 Newton-Raphson load steps. ...
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... static problem the output file is imported and the computed deformed shapes are given in Fig. 10.6 for both models. As it can be seen the derived displacements are 1.14 and 1.15 cm for the 8-noded and 20-noded Hybrid models, respectively. As it was expected the behavior of the Hybrid models is slightly stiffer than those of the unreduced model. Fig. 10.7 shows the four FE models constructed for the purpose of this numerical implementation representation. The RC frame of section 9.2 is used so as to apply the three reduction levels as they are proposed in [2,9]. The material characteristics used in this numerical implementation are those depicted in Table 9.1. The hexahedral elements ...
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... analysis is linear (it doesn't require NR iterations to reach convergence). The number of increments is set equal to 100. That means, that each value of the function will be divided into 100 acceleration steps. In addition, by right clicking in "LoadDyn" and then "Dynamic Analysis", the user sets the dynamic analysis parameters as illustrated in Fig. 13.7. Do not forget to define a high yielding stress that will ensure that the model will never enter the nonlinear state. In "Dynamic Analysis", the "Number of Steps" is set equal to 100 (the same parameter as the number of increments). The "Time per Step" is the Δt that each acceleration increment Figure 13.8 Column. i) Displacement (m) ...
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In this article, the bond performance between recycled concrete and corroded steel bars is analyzed by the nonlinear numerical simulation. The result shows that the maximum bond strength between recycled concrete and steel bar decreases with the increase in steel bar corrosion rate; when the recycled concrete strength is large, the simulated maximum bond strength is in good agreement with the experimental maximum bond strength; when the recycled concrete strength is small, the simulated maximum bond strength is in relatively poor agreement with the experimental maximum bond strength, but there is still an error within the allowable range; the slip between recycled concrete and steel bar increases with the increase in steel bar corrosion rate; when the steel bar corrosion rate exceeded 5%, the bond strength decreases more rapidly; the maximum bond strength increases with the increase in specimen sizes under the same steel bar corrosion rate; the maximum bond strength decreases with the increase in steel bar diameter under the same steel bar corrosion rate.
... This research work attempts to derive an easy to use formula to determine the midspan deflection of real cantilever types of curved steel I-beams with loads applied only at the midspan. A machine learning algorithm that uses nonlinear regression is implemented herein to create a closed-form equation based on midspan deflection results, a dataset developed through the use of Reconan FEA (2020) (Mourlas and Markou, 2020). Prior to the development of the models that were used to train the machine learning algorithm, the software was validated through the use of experimental results found in . ...
