There are two parts included in this report. The first part evaluates the most commonly used test method for adhesive properties, ADTM D 5656 Standard Test Method for Thick-Adherend Metal Lap-Shear Joints for Determination of the Stress-Strain Behavior of Adhesives in Shear by Tension Loading. Finite element analyses were conducted to simulate the specimen behavior following the ASTM procedures. It was found that deviations of the measured adhesive shear modulus from the true value can be as large as 20% if corrections are not made. Correction factors based on different bondline thicknesses and adhesive properties are provided in the report. There are generally three failure modes of adhesive-bonded composite joints: (1) adherend failure, (2) adhesive failure of the adhesive, and (3) cohesive failure of the adhesive. The second part of this report provides (1) an analytical model for predicting stress distributions within an adhesive-bonded composite joint using ASTM D 3165 test specimen dimensions and (2) a method for predicting joint strength under the adherend failure mode. The analytical model was verified using a finite element model and comparing the adhesive stress distributions of the two analyses. A failure analysis was conducted based on four failure criteria. Predicted strengths were compared with test data. It was shown that the maximum inter laminar axial tensile stress criteria predict the joint strength better than Tsai-Hill and von Mises criteria.