TAS::80 0120::TAS PURPOSE, OBJECTIVE, AND BACKGROUND OF WORK TO BE PERFORMED: UNDER THE SUPERSONICS ELEMENT…

Public award description

TAS::80 0120::TAS PURPOSE, OBJECTIVE, AND BACKGROUND OF WORK TO BE PERFORMED: UNDER THE SUPERSONICS ELEMENT OF THE FUNDAMENTAL AERO PROGRAM, NASA LARC HAS BEEN DEVELOPING AND VALIDATING PROGRESSIVE FAILURE METHODS. MUCH OF THE PRELIMINARY WORK INVOLVES TENSILE LOADED COMPOSITE COUPONS WITH CENTER NOTCHES. THE CONVENTIONAL METHOD OF MACHINING THE NOTCHES MAY BE LEADING TO MICRO CRACKS THAT ARE AFFECTING THE FAILURE MECHANISMS AND MAKING IT DIFFICULT TO CORRELATE EXPERIMENTS WITH ANALYSIS. NASA DESIRES TO COMPARE CONVENTIONAL NOTCHED COUPONS WITH THOSE NOTCHED BY LASER CUTTING IN ORDER TO DETERMINE IF THIS IS CAUSING THE OBSERVED PROBLEMS WITH CORRELATION. 3. DESCRIPTION OF THE WORK TO BE PERFORMED: THE CONTRACTOR SHALL PROVIDE ALL THE RESOURCES, INCLUDING LAB RESOURCES, NECESSARY TO PERFORM THE FOLLOWING TASK REQUIREMENTS: 3.1. INITIALLY DEMONSTRATE LASER NOTCH CUTTING CAPABILITY BY CUTTING 3-5 NOTCHES IN COMPOSITE LAMINATE SAMPLE MATERIAL SUPPLIED BY NASA LARC. NOTCHES SHALL BE THROUGH NOTCHES 0.75 INCHES LONG WITH A HEIGHT OF 0.015 INCHES. THE CONTRACTOR SHALL TAKE CARE TO AVOID CHARRING OR DISCOLORATION AROUND NOTCH BOUNDARIES. A METHODOLOGY SHALL BE DEVELOPED TO MINIMIZE THIS PHENOMENON. 3.2. HAVING DEMONSTRATED BASIC TECHNOLOGY ON SAMPLE MATERIAL, THE CONTRACTOR SHALL PROCEED BY CUTTING THREE NOTCHES IN A NASA SUPPLIED THREE INCH WIDE COUPON. NOTCH DIMENSIONS SHALL BE AS FOLLOWS: ONE NOTCH AT 0.75 INCHES BY 0.015 INCHES, ONE NOTCH AT 0.75 INCHES BY 0.03 INCHES AND ONE NOTCH AT 0.75 INCHES BY 0.09375 INCHES. 3.3. PREPARE A SERIES OF NASA SUPPLIED SPECIMENS, EACH WITH A SINGLE CENTRAL NOTCH WITH DIMENSIONS MAINTAINING A NOTCH TO WIDTH RATIO OF 0.25. SPECIMENS OF DIFFERENT LENGTHS WILL BE SUPPLIED BY NASA. THE NOTCH HEIGHTS WILL EITHER BE 0.015 INCHES, 0.03 INCHES, OR 0.09375 INCHES, TO BE DETERMINED BY NASA. 3.4. DEPENDING ON THE SUCCESS OF TESTING SUCH COUPONS, THE GOVERNMENT WILL SUPPLY UP TO 24 ADDITIONAL COUPONS TO BE NOTCHED UTILIZING THE TECHNOLOGY DEVELOPED IN 3.1 THROUGH 3.3 ABOVE. 3.5 THE CONTRACTOR SHALL DEVELOP A PROCEDURE FOR THE LASER CUTTING OF NOTCHES WITH MINIMAL CHARRING EFFECTS. THE PROCEDURE SHALL BE NO MORE THAN 5 PAGES.