In this paper, the total energy release rates for unidirectional glass/epoxy composites were evaluated using Compact Tension Shear (CTS) and Four-Point Bend (FPB) Mixed mode (I/II) fracture specimens. Unidirectional glass fibre laminates were considered for the experimental work. Specimen plates of required thickness were fabricated using hand lay-up technique. The experimental study was conducted for seven loading angles varying from 0° to 90° with an increment of 15° for CTS specimen and 6 crack positions varying from 0 to 1 with an increment of 0.2 for FPB specimen. Load vs. displacement data are plotted to evaluate the peak loads for both the CTS and FPB Mixed mode (I/II) fracture specimens of various loading angles and crack positions, which are utilized to estimate the total energy release rate. It is found that the total energy release rate depends on the loading angle and crack positions for CTS and FPB Mixed mode (I/II) fracture specimens. For a particular load, the total energy release rate is highly dominating in FPB compared with the CTS fracture specimen. Hence, the FPB Mixed mode (I/II) fracture specimen can be preferred over CTS Mixed mode (I/II) fracture specimen to evaluate the total energy release rate.

在本文中，使用紧凑型拉伸剪切（CTS）和四点弯曲（FPB）混合模式（I / II）断裂样品评估了单向玻璃/环氧树脂复合材料的总能量释放率。考虑将单向玻璃纤维层压板用于实验工作。使用手工铺层技术制造所需厚度的样品板。对CTS试样进行了7个加载角（从0°到90°不等，以15°递增）和6个裂缝位置（从0到1，以0.2增量为FPB试样）进行了研究。负载与绘制位移数据以评估不同载荷角度和裂纹位置的CTS和FPB混合模式（I / II）断裂样品的峰值载荷，这些载荷用于估算总能量释放率。结果发现，总能量释放速率取决于CTS和FPB混合模式（I / II）断裂试样的加载角度和裂纹位置。对于特定的负载，与CTS断裂样本相比，FPB中的总能量释放率非常重要。因此，在评估总能量释放率时，FPB混合模式（I / II）断裂样品可能优于CTS混合模式（I / II）断裂样品。