潜水器观察窗用有机玻璃的损伤与破坏行为  

Damage and Failure Behaviors of PMMA used in Deep-sea Submersible Observation Windows

作　　者：郑梦瑶 吴国庆[2] 姜旭胤[2] 张晓雯 丁尧 颜悦 Zheng Mengyao;Wu Guoqing;Jiang Xuyin;Zhang Xiaowen;Ding Yao;Yan Yue(Beijing Engineering Reach Center of Advanced Structural Transparencies for the Modern Traffic System,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;China Ship Scientific Research Center,Wuxi 214082,China)

机构地区：[1]中国航发北京航空材料研究院,北京市先进运载系统结构透明件工程技术研究中心,北京100095 [2]中国船舶科学研究中心,江苏无锡214082

出　　处：《工程塑料应用》2023年第2期126-132,144,共8页Engineering Plastics Application

基　　金：国家重点研发计划项目(2019YFC0311600)。

摘　　要：潜水器观察窗是深海载人潜水器的唯一非金属结构部件,研究该观察窗用有机玻璃材料的损伤破坏行为以及抗裂纹扩展性能对潜水器观察窗使用寿命以及安全可靠性评估具有重要意义。根据观察窗有机玻璃的受载形式,进行拉伸、压缩、剪切、断裂韧性、应力银纹等测试,表征与服役损伤相关的关键力学性能;研究可能出现的损伤缺陷对有机玻璃关键力学性能的影响;结合潜水器观察窗玻璃的损伤缺陷情况,对观察窗用有机玻璃的缺陷(裂纹)扩展性能进行了研究。结果表明,潜水器观察窗用有机玻璃的压缩强度为115 MPa,剪切强度为62.6 MPa,与无机玻璃、定向有机玻璃、聚碳酸酯等材料相比,具有强度高、变形量小、不会突然发生破坏等优势;潜水器观察窗用有机玻璃的抗银纹引发以及抗裂纹扩展的性能较好,应力银纹强度为20.6 MPa、断裂韧性为1.66 MPa·m^(1/2);有机玻璃银纹损伤对拉伸、压缩、剪切静强度基本无影响;与银纹损伤相比,微裂纹缺陷使得压缩屈服强度略有降低但裂纹不扩展,使剪切强度降低约15%且破坏程度剧烈,对拉伸强度影响最大,使其降低约70%。The observation window is the only non-metallic structural component of the deep-sea manned submersible.Studying the damage/failure behaviors and crack propagation resistance of polymethyl methacrylate(PMMA)is significant for evaluating the service life,safety and reliability of deep-sea submersible observation window.Key mechanical properties related to service damage such tensile strength,compression yielding strength,shear strength,fracture toughness,stress craze were characterized in terms of the stress condition of observation windows in service.Also,the influence of possible damage defects on the key mechanical properties of PMMA was researched.At last,combined with the damage and defects of the submersible observation window glass after service,the defect(crack)propagation performance of the PMMA was studied.The results show that the compressive yielding strength of the PMMA for the observation window of the submersible is 115 MPa,and the shear strength is 62.6 MPa.Compared with inorganic glass,oriented PMMA and polycarbonate,the PMMA for the observation window has the advantages of high strength,small deformation,and no sudden damage.Besides,the PMMA has good resistance to crazing initiation and crack propagation,with stress crazing strength of 20.6 MPa and fracture toughness of 1.66 MPa·m^(1/2).The craze damage basically has no effect on the tensile,compressive and shear properties of the PMMA.Compared with the craze damage,the micro-crack defects slightly reduce the compressive yielding strength,while the crack does not grow,the shear strength is decreased by about 15%and the failure mode is severe,the tensile strength is most affected by the micro-crack defects and it is reduced by approximately 70%.

关 键 词：潜水器观察窗 有机玻璃 应力银纹 裂纹扩展 断裂韧性 

分 类 号：U674.941[交通运输工程—船舶及航道工程]