Zouhar Jan, Slaný Martin, Sedlák Josef, Joska Zdeněk, Pokorný Zdeněk, Barényi Igor, Majerík Jozef, Fiala Zdeněk
Institute of Manufacturing Technology, Faculty of Mechanical Engineering, Brno University of Technology, 61669 Brno, Czech Republic.
Department of Mechanical Engineering, Faculty of Military Technology, University of Defence in Brno, 66210 Brno, Czech Republic.
Polymers (Basel). 2022 Apr 26;14(9):1765. doi: 10.3390/polym14091765.
Within the herein presented research, we studied the applicability of flax fabrics for composite parts in personal watercrafts in order to enhance damping of vibrations from the engine and noise reduction (which is relatively high for contemporary carbon constructions). Since the composite parts are intended to be exposed to humid environments requiring high levels of mechanical properties, a carbon-flax composite was selected. Samples of carbon, fiberglass, flax, and hybrid carbon-flax twill and biax fabrics were subjected to tensile and three-point bending tests. The mechanical properties were also tested after exposure of the samples to a humid environment. Damping was assessed by vibration and noise measurements directly on the complete float for samples as well as real parts. The hybrid carbon-flax material exhibited lower values of tensile strength than the carbon material (760 MPa compared to 463 MPa), but, at the same time, significantly higher than the other tested materials, or flax itself (115 MPa for a twill fabric). A similar trend in the results was observed for the three-point bending tests. Vibration tests and noise measurements showed reductions in vibration amplitude and frequency when using the carbon-flax hybrid material; the frequency response function for the watercraft part assembled from the hybrid material was 50% lower than for that made of carbon. Testing of samples located in a humid environment showed the necessity of surface treatment to prevent moisture absorption (mechanical properties were reduced at minimum by 28%). The tests confirmed that the hybrid material is satisfactory in terms of strength and its contribution to noise and vibration damping.
在本研究中，我们研究了亚麻织物在个人水上交通工具复合材料部件中的适用性，以增强发动机振动的阻尼并降低噪音（对于当代碳结构来说，噪音相对较高）。由于复合材料部件旨在暴露于需要高水平机械性能的潮湿环境中，因此选择了碳 - 亚麻复合材料。对碳纤维、玻璃纤维、亚麻以及碳 - 亚麻混纺织物和双轴织物的样品进行了拉伸和三点弯曲试验。在将样品暴露于潮湿环境后，还测试了其机械性能。通过直接在完整浮体上对样品以及实际部件进行振动和噪声测量来评估阻尼。碳 - 亚麻混合材料的拉伸强度值低于碳材料（分别为463 MPa和760 MPa），但同时明显高于其他测试材料或亚麻本身（斜纹织物为115 MPa）。在三点弯曲试验中也观察到了类似的结果趋势。振动测试和噪声测量表明，使用碳 - 亚麻混合材料时振动幅度和频率降低；由混合材料组装的水上交通工具部件的频率响应函数比由碳制成的部件低50%。对置于潮湿环境中的样品进行测试表明，需要进行表面处理以防止吸湿（机械性能至少降低28%）。测试证实，混合材料在强度以及对噪音和振动阻尼的贡献方面是令人满意的。
