- 摘 要
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（1 濰坊科技學(xué)院建工學(xué)院， 壽光 262700； 2 蘭州理工大學(xué)土木工程學(xué)院， 蘭州 730050）
［摘要］基于伸縮斜腹桿施加體外預(yù)應(yīng)力的新加固技術(shù)，以三腹桿體外預(yù)應(yīng)力技術(shù)加固的簡支梁為研究對象，應(yīng)用積分原理和變形協(xié)調(diào)原理，建立了加固后簡支梁的理論模型，推導(dǎo)了撓度與體外索內(nèi)力增量關(guān)系的表達式以及荷載-撓度關(guān)系的表達式；通過數(shù)值模擬方法建立ABAQUS有限元模型，研究了索截面面積、索垂度、索初始內(nèi)力等因素對加固后簡支梁結(jié)構(gòu)性能的影響規(guī)律；后又做了三組試驗，對理論分析和數(shù)值模擬的研究結(jié)果進行了驗證。研究表明：一般地，加固后梁的內(nèi)力以及截面應(yīng)力均發(fā)生重分布，隨著體外索三影響因素（索截面面積、索垂度、索初始內(nèi)力）設(shè)計值的提高，加固后簡支梁的剛度、開裂荷載、極限荷載、結(jié)構(gòu)延性均得到改善，比如在試驗結(jié)果中開裂荷載提高24%～40%、極限荷載提高15%～42%、結(jié)構(gòu)延性提高14%～40%。需要強調(diào)的是體外索設(shè)計參數(shù)的高初始內(nèi)力、小截面、大垂度各工況下，結(jié)構(gòu)發(fā)生脆性破壞的概率會增大，在加固設(shè)計時應(yīng)當(dāng)避免。理論結(jié)果、試驗結(jié)果與模擬結(jié)果僅在彈性階段吻合，而試驗結(jié)果與模擬結(jié)果始終吻合，表明理論推導(dǎo)的體外索內(nèi)力增量公式及彈性階段的承載力公式可靠，能用于工程實踐。
［關(guān)鍵詞］混凝土結(jié)構(gòu)； 簡支梁； 體外預(yù)應(yīng)力； 斜腹桿； 試驗
中圖分類號：TU378-2文獻標(biāo)識碼：A文章編號：1002-848X(2018)18-0093-08
Study of mechanical behavior of external pre-stress concrete simply supported girder beam-cable composite element
Kou Xingting1, Liu Tingyong1,2, Song Yu1,2
(1 Architectural and Civil Engineering Institute, Weifang University of Science and Technology, Shouguang 262700, China；2 College of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China)
Abstract:Based on the new reinforcement technology of external pre-stress with stretch tilted belly poles, the simply supported beam reinforced by the external pre-stress technology of the three titled belly poles was taken as the research object. The integral principle and deformation coordination principle were used to establish a model of reinforced simply supported beam. The expression of the relation between the deflection and the internal force increment of the extra-corporeal cable and the expression of the relationship between the load and deflection were deduced. The ABAQUS finite element model was established by numerical simulation to study the influence rule of the cross-sectional area, cable sag, initial cable internal force and other factors on the structure of reinforced simply supported beams. Then three groups of experiments were organized, and the theoretical analysis and numerical simulation results of the study were validated. The results show that the internal force and the cross-section stress of the beam are redistributed after the reinforcement. With the increase of the design value of the three external factors, the stiffness, cracking load, ultimate load and structural ductility of the simply supported beam are all improved. For example, in the test results, the cracking load increases by 24%～40%, the ultimate load increases by 15%～42% and the structural ductility increases by 14%～40%. Need to be emphasized is that under the high initial internal force of the design parameters of extra-corporeal cable, small section, big cable sag various conditions, the probability of brittle failure of the structure will increase, should be avoided in the reinforcement design. The theoretical results, experimental results and simulation results are in good agreement only in the elastic phase anastomosis，and the experimental results and simulation results always consistent with each other. It indicates that the theoretical derivation of the extra-cordial force increment formula and the elastic stage of the bearing capacity formula is reliable, which can be used in engineering practice.
Keywords:concrete structure; simply supported beam; external pre-stress; tilted belly pole; test
*國家地區(qū)科學(xué)基金（51468040）。
作者簡介：寇興亭，學(xué)士，副教授，Email：wkykxt@163.com。
