The researchers developed a new method for testing composite materials that improves accuracy and reduces errors. By adjusting the notch angle based on the material's properties, they achieved more consistent stress and strain distribution during testing. This led to more accurate measurements of shear properties and strength, with higher shear strengths observed compared to standard testing. The new fixture used in the test also minimized out-of-plane deformation, reducing unwanted stresses. Overall, the new method provides a more reliable way to test composite materials and obtain precise results.