Berkeley Engineering And Research, Inc.
Plures Intelligens Modicum Machinatorem
Telephone: 510-549-3300 
Fax: 510-962-8230 

BEAR Project Receives Award

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BEAR wins Best Paper of the Year

BEAR paper on preventing gasoline can explosions wins Best Paper of the Year

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Alcohol Containers Explode Too!

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Stress Analysis

 
  Near Surface Stress Distributions  |  Through-Thickness Stress Distributions  |  Production Components  
     
 

Residual Stress Measurement

 
 

Residual stress arises from material fabrication, surface treatment and any other process that introduces permanent deformation. They exist independently of external loading and have a significant effect on fracture resistance and component life in many critical applications.

 
     
 

Near Surface Stress Distributions

 
 

BEAR offers a wide range of residual stress measurements that include:

  • near surface stress distributions due to shot peening
  • laser treatment
  • welding
  • machining
  • heat treatment of parts with flat or curved surfaces such as a valve seat inside a valve body, as shown below.
 
   
     
 

Through-Thickness Stress Distributions

 
 

BEAR measures through-thickness stress distributions due to welding, fabrication and heat treatment. Examples include fillet and butt welds, and water-quenched and cladded parts.

Our high-precision, through-thickness residual stress measurements are based on compliance and single-slice methods. The first method uses the strains measured when a cut of progressively increasing depth is introduced by wire electric discharge machining to obtain the stress normal to the faces of the cut. Our second method uses the strains measured when a thin slice is removed from a mid-section of a part to obtain a 2-D distribution of the axial stress.

 
 

 
     
 

Production Components

 
 

BEAR Engineers are available to implement, or assist your engineers in implementing, a proven ultrasonic method to check strategic locations. Our methods are based on refracted longitudinal wave measurements and are calibrated using our high-precision, slice method as well as Finite Element Analysis.