Scaled experimentation can potentially provide significant benefits such as reduced costs materials and time in testing but is afflicted by the phenomena of scale effects, where the behaviour at scale can be markedly different to that at full size. The design of scaled experiments is presently predominantly founded on the theory of dimensional analysis, which itself is grounded on the invariance of dimensionless governing equations with scale. The reality of fracture mechanics however is not invariant equations, but significant deviations and it is evident that scaled-fracture related experiments are presently limited by this affliction.

This paper examines an advance in a new approach to scaled experimentation called finite similitude. The key question addressed here is whether it is possible to overcome the affliction of scale effects by performing not one but two scaled experiments at different scales. It is shown that finite similitude (unlike dimensional analysis) is able to capture all forms of scale dependency, which opens up the possibility of selecting alternative forms of scale invariance and consequently alternative forms of similitude.

First-order finite similitude is investigated in the paper and applied to cracked compact-tension and three-point bending test specimens along with a cracked pressure vessel to illustrate the new concepts. These case studies reveal the veracity and potential of the new approach and highlight possibilities that hitherto would have been deemed impossible with the circumvention of scale effects (as traditionally defined).

规模化实验可能会带来显着的好处，例如降低材料成本和测试时间，但会受到规模效应现象的困扰，规模效应与大规模效应明显不同。目前，规模化实验的设计主要基于维度分析理论，而维度分析理论本身是基于无量纲控制方程的规模不变性。但是，断裂力学的实际情况不是不变方程，而是显着的偏差，很明显，与尺度断裂相关的实验目前受到这种影响的限制。

本文探讨了一种称为有限相似性的规模化实验新方法的进展。此处解决的关键问题是，是否可以通过执行一个而不是两个不同规模的规模化实验来克服规模效应的困扰。结果表明，有限的相似性（与维分析不同）能够捕获所有形式的尺度相关性，这为选择尺度不变性的替代形式以及因此选择相似形式的可能性提供了可能性。

本文对一阶有限相似性进行了研究，并将其应用于破裂的紧凑张力和三点弯曲试样以及破裂的压力容器以说明新概念。这些案例研究揭示了这种新方法的准确性和潜力，并强调了迄今为止规避规模效应（传统定义）的可能性。