不同模量石墨简支梁的弹塑性分析及试验研究

石墨烯是一种强度最大、具有拉压不同弹性模量的材料.石墨是石墨烯的原材料,由于其良好的耐辐照性能,广泛地应用于国防核工业,研究石墨的不同模量力学特性正在成为一种新的研究趋向.实验测试了MSL82型号石墨的力学行为,证明并得到石墨材料的拉压不同模量比值.同时建立了不同模量弯曲梁的弹塑性分析理论模型.通过与测试数据的比较,验证了模型的准确性.研究表明:不同模量石墨梁在弹性阶段,中性轴的位置偏向下方受压侧,但不随荷载变化;拉压模量比对截面的应力分布影响很大,减小拉压模量比,可减小最大拉应力;而增大拉压模量比,则可以减小最大压应力.进入塑性阶段后,随着外荷载的增加,中性层的位置上升,最终的位置由拉压屈服极限的比值决定;随着截面的塑性发展,拉压模量比对截面应力分布的影响逐步减小,但对应变的影响仍然较大.因此,可通过改变拉压模量比来控制截面的最大拉压应变.

Elastoplastic Analysis and Experimental Study of Simply Supported Graphite Beams with Different Moduli

Many materials in engineering have the properties of different elastic modulus in tensile and pressure. In the early 21st century, it was found that the graphene material with the greatest strength has been verified as a material with different modulus of tensile and pressure. graphite is the source material of graphene. due to its good radiation resistance, it is widely used in national defense nuclear industry. studying the mechanical properties of different modulus of materials is becoming a new research trend. By testing the mechanical behavior of MSL82 type graphite, the ratio of different modulus of tensile and pressure is proved and obtained. The elastic-plastic analysis model of curved beams with different modulus is also established. the accuracy of the theoretical model is verified by comparing with the test data. The results show that in the elastic stage, the position of the neutral axis is inclined to the lower compression side but does not change with the load. after entering the plastic stage, with the increase of external load, the position of the neutral layer rises, and the final position is determined by the ratio of the yield limit of the tensile pressure; with the plastic development of the section, the influence of the tensile modulus ratio on the stress distribution of the section decreases gradually, but the influence on the strain is still large. therefore, the maximum tensile strain of the section can be controlled by changing the tensile modulus ratio.