A wooden roller coaster with 80 years of service presented a critical lateral deflection in one of its sections. The initial diagnosis pointed to material fatigue, but the real threat was invisible to the naked eye. Through a combined process of massive 3D scanning with FARO Scene and digitized resistography, engineers discovered internal fungal degradation in the treated pine beams, drastically reducing their ability to withstand lateral forces.
Resistography and Point Clouds: Mapping Internal Degradation 🛠️
The inspection protocol began with capturing a high-density point cloud using the FARO Scene scanner, generating a precise digital twin of the structure. Simultaneously, digitized resistography was applied, a technique that measures the wood's resistance to drilling. This method allowed identifying internal cavities and areas of reduced density caused by the fungus, data that was directly imported into RISA-3D. In RISA-3D, the structure was modeled with the actual beam sections, now weakened, to calculate the loss of load-bearing capacity against lateral stresses. The result was a stress map showing accelerated fatigue at nodes and joints, well below modern safety standards.
The Invisible Passenger: Accumulated Fatigue in Historic Wood 🧐
The temporal deformation analysis, executed in CloudCompare, revealed that the deflection was not a sudden event, but the result of decades of load and humidity cycles. Material fatigue does not manifest only in metal; in wood, the combination of mechanical stress and biological attack creates a silent failure point. This case demonstrates that material fatigue simulation in historic infrastructures must integrate 3D scanning to detect non-visible internal degradation, thus avoiding catastrophic collapses in structures that, at first glance, appear intact.
Which finite element simulation methodology allows for more accurately modeling the differential degradation of wood due to fungal biodeterioration in structural joints under cyclic loads, such as those observed in a century-old roller coaster?
(PS: Material fatigue is like yours after 10 hours of simulation.)