• Particle shape controls fracture force variability and strength estimation.
• μFE model with CIEs accurately simulates particle breakage mechanisms.
• New method normalises fracture force by contact area for consistency in strength measurement.
• Normalised contact area converges across indenter sizes despite variations.
• Smaller indenters cause splitting; larger ones promote chipping behaviour.
Understanding the particle strength is crucial for improving the efficiency, sustainability, and overall performance of processes involving particle breakage. While extensive laboratory testing has provided valuable insights, a consistent method for estimating tensile strength remains elusive. This challenge arises primarily from the complex interplay between geometric and material anisotropy, as well as the inherent heterogeneity of particles, which complicates the standardisation and reproducibility of testing procedures. In this contribution, a point loading test with varying indenter sizes is employed to investigate the effect of contact area on particle tensile strength. A micro finite element (μFE) model is employed to capture the morphology (i.e. shape and size) of real granular materials, incorporating cohesive interface elements to simulate particle breakage. It is observed that the normalised contact area remains independent of indenter size, which motivates the introduction of a correction factor to reconcile variations in tensile strength estimate for the same particle tested with different indenters. The influence of contact area on crushing force, morphological characteristics, indenter size, and fracture mode is systematically analysed. This study provides a framework for optimising tensile strength measurements, which are challenging to achieve through experimental methods alone, and underscores the advantages of the μFE approach in geotechnical research.