The short circuit test is a special test for proving the mechanical integrity of a power transformer. Conventionally a change in reactance exceeding 2% after the test is an indication of failure. Concurrent high frequency excitation is shown to be more sensitive method for detecting winding deformation. A 'benchmark' layer winding is used to validate the use of high frequency excitation. Axial displacement, compression and buckling of the winding are simulated and the changes are identified. It is clearly established that for all these changes high frequency excitation is more sensitive. © 2009 IEEE.