【摘要】：基于起裂韌度擴(kuò)展準(zhǔn)則和黏聚裂縫模型研究混凝土斷裂全過(guò)程中的裂縫尖端黏聚區(qū)特性;利用不同尺寸的帶裂縫三點(diǎn)彎曲梁試件,計(jì)算得到了裂縫尖端黏聚區(qū)的長(zhǎng)度、黏聚力、裂縫張開(kāi)位移等,并采用現(xiàn)有試驗(yàn)成果和有限元方法計(jì)算成果對(duì)本文結(jié)果進(jìn)行了驗(yàn)證。分析結(jié)果表明:最大黏聚區(qū)長(zhǎng)度以及峰值時(shí)刻對(duì)應(yīng)的臨界黏聚區(qū)長(zhǎng)度隨試件尺寸增大而逐漸增大,最大黏聚區(qū)長(zhǎng)度受拉伸軟化曲線(xiàn)影響;裂縫斷裂全過(guò)程曲線(xiàn)受軟化曲線(xiàn)影響較小;當(dāng)外荷載達(dá)到峰值后裂縫張開(kāi)位移近似為線(xiàn)性分布,黏聚力分布受拉伸軟化曲線(xiàn)影響較大。
[Abstract]:Based on the crack initiation toughness propagation criterion and the cohesive crack model, the characteristics of the crack tip adhesion zone in the whole process of concrete fracture are studied. Using different sizes of three-point bending beams with cracks, the length, cohesion force and crack opening displacement at the crack tip are calculated, and the present experimental results and the results of finite element method are used to verify the results in this paper. The results show that the length of the maximum cohesive zone and the critical cohesive zone corresponding to the peak time increase with the size of the specimen, and the maximum length of the cohesive zone is affected by the tensile softening curve. The whole fracture process curve is less affected by the softening curve, and the crack opening displacement is approximately linear distribution when the external load reaches the peak value, and the cohesive force distribution is greatly affected by the tensile softening curve.
【作者單位】： 河北工業(yè)大學(xué)土木與交通學(xué)院;
【基金】：國(guó)家自然科學(xué)基金(51309073) 河北省自然科學(xué)基金(E2014202257) 高等學(xué)校博士學(xué)科點(diǎn)專(zhuān)項(xiàng)科研基金(20131317120012)
【分類(lèi)號(hào)】：TU528.0

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本文編號(hào)：2301903