Composites can be manufactured using either resin transfer ...

Figure 4.3. Experimental test results comparing the Lamb wave response of an undamaged
coupon and coupons with varying hole size.
Another set of tests were conducted to investigate a coupon with a variable number of
holes (1-4) at a fixed diameter of 3.175 mm. The holes were placed 20 mm apart as shown in
Figure 4.4. Sensor output was measured after the addition of each hole and the results are
shown in Figure 4.5.
Figure 4.4. A pictorial representation of a composite coupon with four 3.175 mm diameter
holes illustrating the actuator and sensor placement relative to the holes.
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