New estimationof moldability of stampable sheet molded part by frequency analysis of AE wave.

通过 AE 波频率分析对可冲压片材成型件的成型性进行新评估。

• 批准号: 04650111
• 负责人: FUJIWARA Junsuke
• 金额: $ 1.34万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650111/
• 关键词: Stampable sheet; Heat flow molding; Molding processing; AE; Moldability; Fraquency analysis; キャビティ内圧力; 圧縮成形

The strength of fiber reinforced plastic is affected by molding conditions and has wide dispersion. New method was developed with AE on order to estimate the moldability of stampable sheet. The stampable sheet used in this study is composed of polypropylene resin and chopped strand glass fiber. The virious stampable sheets, which had four kinds of glass fiber length, four kinds of fiber content and four kinds of fiber dispersion, were prepared. Thespecimens were molded form these molding materials and were investigated in order to clarify the fracture mechanism in detail. An AE sensor was attached on a test piece with wax. The forty AE waves were measured during one bending test. Then, these AE waves were analyzed with FFT, and each power spectrum was calculated. Consequently the characteristic frequency corresponding to the each frcture states were revealed. That is to say, it is considered that the frequency of 85kHz is generated in the fracture of a glass fiber, the frequency of 65kHz is generated in the fracture of martix (PP), the frequency of 105kHz is generated in the pull-out of a glass fiber from the natrix with slip, the frequency of 135kHz is geverated in the pull-out of a glass fiber from a glass fiber bundle and the frequency of 160kHz is generated in the interface debonding of a glass fiber from the matrix. In order to clarify the relation between the fracture and the frequency, micro tensile test in SEM was carried out. It was clear that the frequency around 135kHz was generated in the pull-oout of a glass fiber from a glass fiber bundle and the frequency around 105kHz was generated in the interface debonding of a glass fiber from the matrix.

纤维增强塑料的强度受成型条件的影响，具有广泛的分散性。提出了一种利用声发射技术评价可冲压板材可塑性的新方法。本研究使用的可冲压片材由聚丙烯树脂和短切玻璃纤维组成。制备了具有4种玻璃纤维长度、4种纤维含量和4种纤维分散度的病毒可压片。用这些模塑材料对试件进行了模塑，并对其断裂机理进行了详细的研究。用蜡将声发射传感器附着在试件上。在一次弯曲试验中测量了40个声发射波。然后，对这些声发射波进行FFT分析，计算各波的功率谱。从而得到了各断裂状态对应的特征频率。也就是说,认为85 khz的频率在玻璃纤维的断裂,生成65 khz的频率产生的裂缝martix (PP),生成105 khz的频率在玻璃纤维的拉拔力从natrix滑倒,135 khz的频率geverated撤军的玻璃纤维玻璃纤维束和160 khz的频率生成界面脱胶的玻璃纤维的矩阵。为了弄清断裂与频率的关系，在扫描电镜下进行了微拉伸试验。很明显，135kHz左右的频率是在从玻璃纤维束中拔出玻璃纤维时产生的，105kHz左右的频率是在玻璃纤维与基体的界面脱粘时产生的。