Structural Inspections Are Not Failing Because of Steel
Failures result from a lack of understanding of steel. Falk PLI measurement methods can help improve your understanding of your structures.
By Mike Falk, Falk PLI
Structural inspections are often considered a solved problem due to methodologies, established codes, standards, and certification programs. However, major structural failures still occur, sometimes soon after an inspection reports “no critical issues.”
This disconnect is not coincidental and is not primarily a materials issue.
It is a measurement problem.
The Industry Continues to Rely on Human Vision as the Primary Sensor
Most structural inspections are still driven by human observation. Inspectors climb, crawl, or fly drones and visually search for cracks, corrosion, or section loss. Those inspections are performed in settings that are cold, hot, dark, elevated, noisy, and frequently rushed.
Studies have repeatedly shown that visual inspections do not yield consistent results. What an inspector sees is influenced by experience, physical condition, lighting, and the ease of access to the structure. As a result, many in the structural monitoring field now acknowledge that training alone cannot eliminate the uncertainty inherent in visually driven inspections.
From a metrology perspective, that is equivalent to using a sensor with unknown bias and inconsistent repeatability. No engineer would accept that in a laboratory. Yet it is still common practice in the field.
Cracks Are a Late Signal, Not an Early Warning
One of the biggest misconceptions in inspection is treating cracks as the primary indicator of distress.
Cracks are not the starting point of failure. They show up after a structure has already deformed, rotated, or yielded in localized areas. Long before a crack is easy to see, the geometry has changed in ways that cannot be reversed. That reality is driving more researchers to focus on movement and shape change rather than surface damage.
Why Sparse Measurements Force Assumptions
Traditional inspections and surveys rely on a small number of discrete points. Engineers then fill in the gaps with assumptions about loading, continuity and behavior.
Assumptions are not measurements.
High-density laser scanning produces millions of data points that describe actual geometry, not inferred geometry. When deformation is measured directly, assumptions are no longer standard practice.
This is not an incremental improvement. It is a change in inspection philosophy.
Why Falk PLI
Falk PLI uses laser metrology as a measurement system, not merely as a documentation tool.
Our work focuses on:
Measuring distortion, not just damage
Capturing loaded and unloaded behavior
Decreasing human factor error through objective data
Providing engineers with evidence, not opinions
This approach enables clients to identify structural issues earlier, improve maintenance planning, and avoid the false confidence that visual inspections may create.