Passengers of a recently constructed skyscraper reported metallic noises and anomalous vibrations when reaching 20 meters per second. After multiple failed inspections, a 3D scan with Leica Infinity revealed the cause: a millimetric deviation in the guide rails, caused by the differential thermal deformation of the building. This defect generated a dangerous resonance between the structure and the elevator cabin.
Construction of the digital twin and resonance simulation 🏗️
The engineering team built a digital twin of the building and the elevator system using Autodesk Fusion 360 for detailed mechanical modeling of the cabin, pistons, and rails. The point cloud data from the Leica scan was integrated directly into SAP2000 to recreate the real geometry of the building, including the thermal curvature. When running the dynamic simulation, the model exactly reproduced the reported vibration frequency. It was identified that the differential expansion of the sunny side of the building generated a structural wave that excited the natural frequency of the hydraulic piston, amplifying the noise and jolt.
Virtual validation of the solution without physical risks 🛠️
The advantage of the digital twin was being able to test solutions without intervening in the real building. Two approaches were simulated: the installation of tuned mass dampers on the cabin frame and the micromachining of the rails to compensate for the thermal deviation. The simulation in SAP2000 showed that the combination of both methods reduced the vibration amplitude by 87%. The final solution was implemented in the real elevator, eliminating the noise and discomfort, thus validating the predictive power of the digital twin in critical systems engineering.
How did the digital twin manage to identify and correct the lethal vibrations in the skyscraper elevator before they caused a catastrophic failure?
(PS: My digital twin is right now in a meeting, while I am here modeling. So technically, I am in two places at once.)