GB/T 28891-2012 Focused fiber reinforced plastics composite performance testing, specifies the determination method of unidirectional reinforced materials type ⅰ interlayer fracture toughness GIC. Applicable to this type of composite products. The standard clarifies the determination principle, introduces the requirements of electronic Universal Testing Machine and other equipment, and details the sample preparation, including material laying, dimensional accuracy, etc. Standardize the loading test steps, and clarify the data recording and processing methods to calculate the GIC value. This standard provides a unified means for evaluating the fracture resistance of material layers, helps to improve the composite mass of fiber reinforced plastics, and promotes the technological progress of related industries.