This analysis does not cover the causes of all possible frame problems. However, it may provide valuable assistance with preparing reports.

Frame damage does not happen without a cause. The cause of damage is not always as apparent as it may be in a collision.

Frame damage may be broken up into the following classifications:

Repair the damage caused by a collision by using the proper methods and reinforcements.

Excessive bending movement damage is caused by overloading, improper weight distribution, or misapplication of the vehicle. Excessive bending movement damage will occur at different areas on various types of vehicles.

For information on localized stress concentration, refer to Stress Concentration.

Localized stress concentration failures may result from bending movement stresses. However, the stress levels would not be high enough, in the aforementioned instances, to cause any difficulty without localized stress concentration points. These localized stress concentration points may result from poor body mounting, special equipment, or defective material. They may also occur as a result of high bending loads, coupled with severe torsional loads such as off-road service.

Use wood sills between the main rails and the sub-frame on the body installation in order to ensure a satisfactory load distribution.

Special equipment or accessory installation may cause high stress concentrations due to the method of attachment or the weight of the equipment. Do not drill holes through the flanges. Avoid rapid changes to the section modulus that usually occur when large mounting plates are added for the support of special equipment. Mounting heavy equipment across the flanges or on the web of a side rail may cause enough stress concentration to cause damage at any of the following locations: