PSI - Issue 64

Iryna Rudenko et al. / Procedia Structural Integrity 64 (2024) 1216–1223 I. Rudenko and Y. Petryna / Structural Integrity Procedia 00 (2019) 000–000

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from the IFC file. Secondly, if the sensors are defined and connected to the current element, their positions will be retrieved. If the current element from the BIM model should be meshed with beam elements, a node will be generated on the position of the sensor. If the desired FE dimensionality is 2D or 3D, an APDL command will be written to the macro file to find the nearest node to the sensor. This could be useful to simulate the sensor data in FE software. Afterwards, the geometry of the current element will be extracted. Depending on the required FE dimensionality, the corresponding APDL commands related to geometry and material properties will be generated. Then, the positions and boundary conditions of the structural connections related to the current element will be obtained and APDL commands regarding meshing and boundary conditions can be produced. All available structural connection types (point, curve and surface) are supported. Moreover, spring elements could be generated for structural point connections. Once the iteration over all elements ends, an ANSYS APDL file is written and can be imported into ANSYS for structural analysis. 3.5. Example The proposed approach for BIM-based FE model generation including SHM relevant information is illustrated by an example of a laboratory test structure. The structure is a double overhanging beam with rectangular hollow cross section made of stainless steel. The total length of the beam is 4.4 m. The acceleration of the structure in vertical direction was measured by using three sensors and the shaker was used to generate the vibrations. The first natural frequency was identified at 4.52 Hz. Afterwards, the BIM model of the beam containing material properties, structural supports as well as sensors was created using Blender and is shown in Fig. 4. The sensors are represented as orange bricks in the BIM model. The left support is a roller support and the right one is a pin support. The created IFC file was used to generate different FE models with beam, shell and solid finite elements. The FE models with beam and shell finite elements are shown in Fig. 5. All information required for FE analysis in ANSYS APDL was automatically extracted from the IFC file. Only the commands related to modal analysis and post-processing were added manually to the APDL file. Subsequently, modal analysis was conducted without an additional mass of the shaker. All FE models show the same results and the first calculated natural frequency equals to 5.86 Hz, which differs from the measured frequency by 30 %. Since a shaker was used to generate the vibrations, the BIM and FE models were adjusted by adding a mass of 4 kg in the middle of the beam. After this adjustment, which also covers the transverse elements in the middle of the beam, the calculated value of the first eigenfrequency approaches to 4.57 Hz and shows a good agreement with experimental results. This example was used to demonstrate and validate the presented approach for BIM-based FE model generation and give a first idea how BIM, SHM and FEM can be combined. The BIM model of the test structure was established and FE models with different FE dimensionality were generated automatically from the IFC file. After that, the modal analysis was conducted in ANSYS APDL and the FE models were validated. Subsequently, the changes made to the FE models were manually introduced back to the IFC file. The future work will include the tests with more complex structures and consideration of damages within the BIM as well as the FE models.

Fig. 4. BIM model of the laboratory test structure.