LASER MEASURING DEVICE Team Members:Don Ainsworth David Linder Sagar Mathur Bokah Worjoloh Customer: United States Army Mission: Conceptualize, design, build, implement and validate an automated computer-controlled laser measuring device for growth characterization in composite materials. Advisor: Dr. Ajay K. Prasad Approach: Use wants, constraints, benchmarking, and metrics as tools in developing a quality design.

CUSTOMERS n Travis Bogetti - US Army. n John Gillespie - Technical Director of CCM. n Tong Wang - Graduate Student at CCM. n Florella Flores - Graduate Student at CCM.

BENCHMARKING n Laser Flaw Measuring Device (UD Physics Department) n Universal Length Measuring Instrument n Zeiss CMM n Topometrix Atomic Force Microscope n 5-D Laser Measuring System

CUSTOMER WANTS n Measure 0.5% strain in a 1/10 inch sample. (~15 microns) n Quantify measurement accuracy of device. n Measure average thickness of sample. n Measure cure shrinkage of resin. n Measure warpage of resin cure on aluminum.

CUSTOMER WANTS(2) n Measure samples of various dimensions (thickness/width) n Verify laser measurement data. n Store and manipulate data. n Easy to use. n Use in lab setting.

CONSTRAINTS n Use of Laser System already purchased - Keyence LC-2440 System. n Cost - $2,000 to $3,000. n Completion Time - May 1998.

METRICS n Obtain an overall accuracy of at least +/- 5 microns. n Obtain at least 1725 data points when determining the average. n Ability of the device to translate the sample continuously for at least 10 in. n Sample orientation zero (+/- 0.5) degrees from the horizontal.

METRICS (2) n Ability of the device to accommodate samples that are 10x10x5/8 inches. n Have 10K bytes of disk space. n Take no more than 20 minutes to measure a sample. n Operating conditions: Temp C, Humidity of 35-80% no condensation.

PROBLEM BACKGROUND n Composites undergo significant dimensional changes. n Faster and more accurate measuring methods needed to better characterize growth.

CONCEPT GENERATION n Concept 1: –Modify and characterize existing device to determine average thickness using random scan lines. n Concept 2: –Use servo-motors, slides and a control system to measure and compare thickness’along exact scan lines.

PROTOTYPE n Hardware Design –Vertical Stand –Gripper –Holding fixtures n Software Design –Running Average and Standard deviation –Write data to file n Operation of Laser System (Overview)

TESTING n Sample selection criterion. n Determine magnitude of error in average and absolute thickness measurements. –Error due to vibrations Stationary Data at a point (Average/No Average) –Error due to incomplete convergence of the mean. Scanning data

TESTING (2) n Verification of thickness data. –Shim stock measurement. n Warpage Experiment. –Measured deflection of aluminum due to surface resin cure.