Structural and Frame Damage Analysis
Structure and measurement
Structural analysis asks whether the vehicle's platform - rails, aprons, strut towers, rockers, floor, pillars, and unibody - has moved beyond tolerance. Candidates must understand datum, centerline, and control points, and that modern vehicles are measured against manufacturer specifications using a measuring system (mechanical or electronic). Understand sway, mash, diamond, twist, and side sway as classic misalignment patterns.
Repair vs. replace at the structural level
Know that structural repair requires pulling to specification, sectioning per OEM procedures, and restoring crush zones and welded joints with correct weld type and count. Understand that some structural components are replace-only and that recycled structural parts may be prohibited. Understand airbag and restraint implications - structural damage often triggers restraint inspection.
Traps
A frequent trap is assuming a vehicle with no visible frame bend is structurally sound - measurement is required. Another is treating a sectioning location as arbitrary; OEM procedures specify where and how. Watch for questions that ignore weld count or crush-zone restoration.
Worked example / rule of thumb
Rule of thumb: if structural damage is suspected, measure before you estimate structural labor. Example: a front-corner hit with a tight door gap and a shifted hood - measure rails and aprons against datum; if a rail is out of tolerance, estimate pull-to-spec, then re-measure, then repair or replace per OEM procedure.