A series of mode I fracture toughness tests employing the semi-circular bend (SCB) and the pseudo-compact tension (pCT) methodologies have been performed with two sandstone types and specimens of 50 and 100 mm in diameter. The tests were complemented with the concurrent monitoring of acoustic emission (AE) activity using a multi-sensor array. With the obtained data, we compare and analyse the two testing methods, the mechanical evolution along experiments and the significance of different acoustic emission parameters. The hypocenter location of the AE events allows a better understanding of the processes occurring in the tests and the analysis of properties like amplitude or peak frequencies are valuable complements. Crack modes are assessed using a parameter-based strategy (comparison of the average frequency, AF, and rise angle, RA), and the potential of the Ib-value to discriminate cracking processes in fracture toughness tests is explored. Results show that the pCT method provides more comprehensive and detailed results, both in terms of mechanical information and acoustic emission data. We discuss the applicability of the generally accepted models of small-strain brittle material failure typically applied to compressive tests (including or not AE data) and further methodological questions of interest when considering AE monitoring in fracture toughness tests.

使用半圆弯曲（SCB）和拟紧凑张力（p用两种砂岩类型和直径分别为50和100 mm的标本进行了CT）方法学研究。使用多传感器阵列同时监测声发射（AE）活性，对测试进行了补充。利用获得的数据，我们比较并分析了两种测试方法，沿实验的机械演变以及不同声发射参数的重要性。AE事件的震中位置可以更好地了解测试中发生的过程，并且对振幅或峰值频率等属性的分析是有价值的补充。使用基于参数的策略（平均频率AF和上升角RA的比较）以及I b值的潜力来评估裂纹模式探索了在断裂韧性测试中区分开裂过程的方法。结果表明，p CT方法在机械信息和声发射数据方面都提供了更全面，更详细的结果。我们讨论了通常用于压缩试验（包括或不包括AE数据）的普遍接受的小应变脆性材料破坏模型的适用性，以及在断裂韧性试验中考虑进行AE监测时感兴趣的其他方法学问题。