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

先进复合材料壁板的面内剪切试验方法由于难以给出均匀的应力场和可靠的剪切性能而在国际上尚未得到认可，本文对传统的画框加载法进行了几点修正，使其适用于面内剪切试验方法。为了验证这些修改的优点，进行了单向和布筋碳纤维布试件的试验和有限元数值分析。结果表明，与传统的简单画框夹具、二轨或三轨夹具以及JIS方法相比，由于沿沿着和角部没有大的应力集中，因此获得了均匀的剪应力状态，从而获得了可靠的较高的抗剪强度。也就是说，在这些最广泛使用的抗剪试验中，由于应力集中和应力分布不均匀而导致过早破坏，因此获得了较低的抗剪强度。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