Loading patent…
AssigneeThe Boeing Company
InventorsMitchell J. Lee, Nicklaus Cummings Kimball
Estimating the term…
A coupon geometry that reliably fails in the gauge area of the coupon during fatigue testing. The propensity to fail at the gauge area is imparted by using a bow-tie-shaped coupon coupled with similarly shaped tabs. The test coupons have a bow-tie-shaped profile with tapered sides that converge as they extend from the opposing ends of the coupon to the gauge area, forming a pair of trapezoidal portions (one the mirror image of the other) connected by the gauge area. These trapezoidal portions of the test coupon include the regions where similarly trapezoidal tabs will be adhered to the front and back of the coupon. The test coupon has a minimum width in the gauge area and a constant thickness, and a height of the gauge area is no greater than 3% of a height of the test coupon.
A composite test coupon comprising:
A composite test coupon having a constant thickness, a height along a vertical axis, and a bow-tie-shaped profile when viewed along an axis in a thickness direction, wherein said bow-tie-shaped profile comprises left and right sides and top and bottom ends, said left side comprising a first radiused portion and first and third straight tapered portions extending from said first radiused portion toward said top and bottom ends respectively, and said right side comprising a second radiused portion and second and fourth straight tapered portions extending from said second radiused portion toward said top and bottom ends respectively, said first and second straight tapered portions extending from said first and second radiused portions respectively in mutually diverging first and second directions, and said third and fourth straight tapered portions extending from said first and second radiused portions respectively in mutually diverging third and fourth directions, wherein a taper angle between said first straight tapered portion and an intersecting line parallel to said vertical axis is in a range of 1 to 10 degrees inclusive.
A test coupon assembly comprising:
Dependencies are inferred from the claim text.