Sharma Aashish, Leib-Day Alexia R, Thakur Mohmad Mohsin, Penumadu Dayakar
GEOServices LLC, Cleveland, TN 37312, USA.
Dan Brown and Associates, PC, Knoxville, TN 37919, USA.
Materials (Basel). 2021 Jun 2;14(11):3023. doi: 10.3390/ma14113023.
Stress-strain and volume change behavior for clean sands which have distinct particle shape (rounded and angular) with very similar chemical (mineralogical) composition, size, and texture in one-dimensional (1D) compression and drained triaxial compression are presented. The effect of particle morphology on the crushing behavior in one-dimensional loading is explored using laser light diffraction technique which is suitable for particle crushing because of its high resolution and small specimen volume capability. Particle size distribution in both volume/mass and number distributions are considered for improved understanding associated with the process of comminution. Number distributions present a clearer picture of particle crushing. It is argued that particle crushing in granular assemblies initiates in larger particles, rather than in smaller particle. It was found that rounded sand specimens showed greater crushing than angular sand specimens with higher uniformity coefficient. In 1D compression, loose specimens compress approximately 10% more than dense specimens irrespective of particle shape. Densification of angular sand results in improvement in stiffness (approximately 40%) and is comparable to that of loose rounded sand. In general, density has a greater influence on the behavior of granular materials than particle morphology. The effect of particle shape was found to be greater in loose specimens than in dense specimens. The effect of grain shape on critical state friction angle is also quantified.
本文给出了在一维压缩和排水三轴压缩条件下，具有不同颗粒形状（圆形和棱角形）但化学（矿物学）组成、尺寸和纹理非常相似的纯净砂的应力-应变和体积变化行为。利用激光衍射技术研究了颗粒形态对一维加载下破碎行为的影响，该技术由于具有高分辨率和小试样体积能力，适用于颗粒破碎研究。考虑了体积/质量分布和数量分布中的粒度分布，以更好地理解粉碎过程。数量分布能更清晰地呈现颗粒破碎情况。研究认为，颗粒集合体中的颗粒破碎始于较大颗粒，而非较小颗粒。研究发现，具有较高均匀系数的圆形砂试样比棱角形砂试样表现出更大的破碎程度。在一维压缩中，无论颗粒形状如何，松散试样的压缩量比密实试样大约多10%。棱角形砂的致密化导致刚度提高（约40%），与松散圆形砂相当。总体而言，密度对粒状材料行为的影响比颗粒形态更大。发现颗粒形状在松散试样中的影响比在密实试样中更大。还量化了颗粒形状对临界状态摩擦角的影响。
