Research on Mechanical Testing Method for In-plane Shear Properties of Advanced Composite Materials

先进复合材料壁板的力学面内剪切试验方法因其难以呈现均匀的S应力场和可靠的剪切性能而被国际认可，本文对传统的画框加载装置进行了几次修正，以用于面内剪切试验方法。进行了CFRP单向试件和布加固CFRP试件的试验，并进行了有限元数值分析，以验证各种修正方法的优越性。结果表明，与传统的简单边框夹具、两轨或三轨夹具和JIS方法相比，TES方法获得了均匀的剪应力状态和可靠的更高的剪切强度，因为在边角和角部没有很大的应力集中。也就是说，在目前应用最广泛的剪切试验中，由于应力集中和应力分布不均匀导致的早期破坏，得到的抗剪强度较低。此外，在单向复合材料的复合应力条件下，JIS方法似乎没有给出剪切断裂。

The mechanical in-plane shear testing method for advanced composite panels has yet been authorized internationally because of its difficulty to present the uniform s stress field and the reliable shear properties.In the present paper, the several revisions of the traditional picture-frame loading fix is proposed to use for the in-plane shear testing method. The experiments on unidirecti and cloth-reinforced CFRP specimens and the numerical analyses by use of FEM were perfo in order to verify the advantages of these various revisions. As a result, the uniform shear stress state and hence the reliable higher shear strengths were obtained, because t is no large stress concentrations along edges and at corners, compared with other tes methods which used the traditional simple picture-frame fixture, two-rail or three-rail fixtures and JIS methos. That is, in these shear tests which are used most widely at pres the lower shear strengths were obtained because of the premature failure due to st concentration and nonuniform stress distribution. Further, it seemed that JIS method for did not give a shear fracture under combined stress conditions in unidirectional composite