当前位置: X-MOL 学术Dent. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Fracture mechanics of circular discs with a V-notch subjected to wedging.
Dental Materials ( IF 5 ) Pub Date : 2020-01-31 , DOI: 10.1016/j.dental.2020.01.010
Wondwosen Aregawi 1 , Brian W Darvell 2 , Alex S L Fok 1
Affiliation  

OBJECTIVE A method proposed for determining the fracture toughness (FT) of dental materials involves a 'roller' wedging open a V-notch in a cylindrical specimen. There are a number of problems with the design of this test and its mechanical analysis, and thus with the validity of the results obtained, were it to be used. Firstly, friction is ignored in calculating the horizontal wedging force. Secondly, the test specimen does not make use of a pre-crack at the notch tip. The aim of this study was to evaluate the effects of these factors on the FT calculated. METHODS An analytical solution for the mode-I stress intensity factor (KI) of the compact tension specimen, which bears some similarities, is taken to be applicable. The mechanics of the specimen has been reanalysed, with a finite-element study of the resultant stresses, and compared with the compact-tension test. RESULTS The assumed analytical solution can provide accurate estimates for KI for the V notched specimen. However, the apparent agreement is due to the fortuitous combination of an overestimated horizontal wedging force and an underestimated stress singularity at the crack tip. In any case, ignoring friction will lead to an overestimate of FT. SIGNIFICANCE It is concluded that the test as presented is invalid.

中文翻译:

带楔形的V型圆盘的断裂力学。

目的提议的一种用于确定牙科材料的断裂韧性(FT)的方法涉及“滚子”楔入圆柱形试样中的V形缺口。使用此测试时,该测试的设计及其力学分析存在许多问题,因此,对于所获得结果的有效性也存在许多问题。首先,在计算水平楔入力时忽略了摩擦。其次,试样在缺口尖端处不使用预裂纹。这项研究的目的是评估这些因素对计算的FT的影响。方法采用紧凑型拉伸试件的I型应力强度因子(KI)的解析解具有相似之处,可以应用。对试样的力学进行了重新分析,并对所得应力进行了有限元研究,并与压实试验进行比较。结果假定的分析解决方案可以为V型缺口样品的KI提供准确的估计。但是,明显的一致是由于高估了水平楔入力和低估了裂纹尖端处的应力奇异性所造成的。无论如何,忽略摩擦都会导致FT高估。重要性结论是所提出的测试无效。
更新日期:2020-01-31
down
wechat
bug