Self-monitoring metals, alloys and materials

Abstract

Observability of damage precursor, damage and usage states, or event occurrence may be enhanced by modifying component materials to include self-monitoring materials or by processing test material to alter the surface properties. The properties of the self monitoring materials, such as magnetic permeability or electrical conductivity, are monitored with electromagnetic sensors and provide greater property variations with component condition than the original component material. Processing includes shot peening or laser welding.

1 . A method for monitoring a structural component during a towing procedure, said method comprising: 
 placing at least one sensor proximate to the structural component, the at least one sensor being oriented to be sensitive to a material property that changes with a load;    measuring said material property with the sensor;    correlating said material property to the load; and    monitoring the load during the towing procedure.    
   
   
       2 . The method as claimed in  claim 1  further comprising: 
 mounting the at least one sensor to a structural component surface.    
   
   
       3 . The method as claimed in  claim 2  wherein at least one sensor is held in place by a fixture connected to the structural component.  
   
   
       4 . The method as claimed in  claim 1  further comprising: 
 monitoring the load for an overload condition.    
   
   
       5 . The method as claimed in  claim 1  further comprising: 
 monitoring said material property for damage.    
   
   
       6 . The method as claimed in  claim 1  further comprising: 
 placing a second sensor proximate to the structural component, the second sensor being oriented to be insensitive to the material property that changes with the load.    
   
   
       7 . The method as claimed in  claim 1  further comprising: 
 adjusting the towing procedure to ensure that the monitored load is within an acceptable range.    
   
   
       8 . The method as claimed in  claim 7  wherein the adjusting is performed automatically.  
   
   
       9 . The method as claimed in  claim 1  wherein the at least one sensor is an eddy current sensor.  
   
   
       10 . The method as claimed in  claim 1  wherein the at least one sensor is an eddy current sensor array.  
   
   
       11 . The method as claimed in  claim 1  wherein the material property is an electrical property.  
   
   
       12 . The method as claimed in  claim 11  wherein the electrical property is magnetic permeability.  
   
   
       13 . The method as claimed in  claim 12  wherein the at least one sensor has a permanent magnet.  
   
   
       14 . The method as claimed in  claim 11  wherein the electrical property is electrical conductivity.  
   
   
       15 . The method as claimed in  claim 1  further comprising: 
 placing a coating on the structural component with a second material that has a larger material property variation with load than the structural material.    
   
   
       16 . The method as claimed in  claim 15  wherein the second material is an austenitic stainless steel.  
   
   
       17 . The method as claimed in  claim 15  wherein the at least one sensor is a dielectric sensor.  
   
   
       18 . The method as claimed in  claim 1  wherein the structural component is a landing gear of an aircraft.