STRUCTURAL DESIGN CORPORATION

Structural Safety Professionals to General Industry  

We can help make your facilities safer

Starting with the structural design of Ash Handling Structures for coal fired electrical generating plants in 1979 to the design of OSHPD code required seismic restraints for California hospitals in 1989, SDC has become a leader for structural safety in the steel industry.

For over 30 years SDC has studied the behavior of EOT Crane Girders.  Our structural inspection experience of crane runways matches our crane girder failure analysis results using CRANE GIRDER PRO. CRANE GIRDER PRO performs a complete torsional and fatigue assessment analysis of unsymmetrical crane girders. This includes calculation of the Shear Center, Torsional Warping Constant (Cw), and Plastic Modulus (Zx and Zy) for the unsymmetrical cross section.  CRANE GIRDER PRO can also compute torsional stress from poor Crane Rail Alignment. 

Crane girders in all Class A Buildings are subject to failure.

Why Do Crane Girders Fail?

Singly symmetric and unsymmetrical cross sections need to be designed by performing a full, detailed torsional and fatigue analysis. Other Design methods such as Flexural Analogy found in AIST Technical Report 13 or Finite Element analysis do not work. All loads including the dead weight of the crane rotate about the girder shear center. This is how tension forces are created in what is normally the compression zone of a girder.

Some failures prior to girder repair or replacement could be classified as near misses by OSHA.

CRANE GIRDER PRO allows SDC to determine Why Crane Girders Fail.Knowing Why Crane Girders Fail affects:

• Overhead Crane Safety
• Crane Runway Repair
• Crane Runway Inspection and Maintenance
• Crane Runway and Crane Rail Alignment

SDC performs forensic analysis of crane girder failures and designs torsion and fatigue resistant replacement crane girders. Some of our replacement crane girders were installed prior to total collapse of the original girders.

This website describes How Crane Girders Fail along with the relationship between EOT cranes and crane girders.

Crane girder failure is caused by torsion and fatigue.