56 / 57 . " Improved Methodology for Axial Force Prediction at Angle of Attack, " AIAA Paper 98-0579, 36th Aerospace Sciences Meeting, Jan 1998 and JSR Vol . 35, No . 2, March April 1998, pp 132 139 ( written with T . Hymer ).
32.
An influence line for a given function, such as a reaction, axial force, shear force, or bending moment, is a graph that shows the variation of that function at any given point on a structure due to the application of a unit load at any point on the structure.
33.
Although back protectors, as defined in the standard, cannot protect against axial forces they are required to protect the scapula and there is now considerable anecdotal evidence that wearing a certified back protector can significantly reduce trauma in a major accident as they reduce the effect of impacts on the ribs and lessen the blows to internal organs too.
34.
Most screws are designed to be self-locking, and in the absence of torque on the shaft will stay at whatever position they are left . However, some screw mechanisms with a large enough pitch and good lubrication are not self-locking and will overhaul, and a very few, such as a push drill, use the screw in this " backwards " sense, applying axial force to the shaft to turn the screw.
