Witzgall Christian, Gadinger Marc, Wartzack Sandro
Engineering Design, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
Materials (Basel). 2023 Sep 12;16(18):6174. doi: 10.3390/ma16186174.
It is undeniable that mechanical properties, such as the stiffness or residual strength of fibre-reinforced thermoplastics, are adversely affected by fatigue damage caused by cyclic loading. In order to quantify and predict this damage influence, a calculation approach was developed in the past for the subgroup of short-fibre-reinforced thermoplastics. In order to test and expand the applicability of this approach to the field of long-fibre-reinforced thermoplastics, the decrease in mechanical properties is investigated experimentally in this paper using PP LGF30, propylene reinforced with long glass fibres, as an example. The paper describes both the fatigue behaviour and the residual strength of the material after fatigue damage. A decrease in the residual strength of up to about 35% could be recorded. The paper also presents a modelling approach that predicts the orientation-dependent fatigue strength of the material, and furthermore allows for the calculation of its residual strength as a function of fatigue damage. The novelty of the contribution lies in the continuous modelling of fatigue behaviour for arbitrary oriented samples of long-fibre-reinforced thermoplastics and also in the prediction of its residual strength depending on previously induced fatigue damage.
不可否认，纤维增强热塑性塑料的机械性能，如刚度或残余强度，会受到循环载荷引起的疲劳损伤的不利影响。为了量化和预测这种损伤影响，过去针对短纤维增强热塑性塑料这一类别开发了一种计算方法。为了测试并将该方法的适用性扩展到长纤维增强热塑性塑料领域，本文以长玻璃纤维增强的聚丙烯PP LGF30为例，对其机械性能的下降进行了实验研究。本文描述了材料的疲劳行为以及疲劳损伤后的残余强度。记录到残余强度下降高达约35%。本文还提出了一种建模方法，该方法可预测材料的取向相关疲劳强度，此外还能根据疲劳损伤计算其残余强度。该贡献的新颖之处在于对长纤维增强热塑性塑料任意取向样本的疲劳行为进行连续建模，以及根据先前诱导的疲劳损伤预测其残余强度。
