薄壁箱梁的剪切附加挠度分析
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摘要
从薄壁箱梁弯曲剪力流出发,分析箱梁的应力应变关系,并与初等梁理论相结合,导出适合薄壁箱梁的合理剪切参数,从而简化箱梁腹板剪切附加挠度的计算.采用对剪切附加曲率的积分及能量变分法,导出腹板剪切附加挠度和考虑全截面剪切变形的箱梁挠度计算公式.通过剪切附加挠度与弯曲挠度的对比,分析影响翼板和腹板剪切变形的主要因素.建立了ANSYS空间模型算例,结果表明,按本文的计算式所得挠度与ANSYS结果吻合良好;当宽跨比、高跨比较大时,均布荷载作用下的简支箱梁跨中因剪切变形产生的附加挠度将达弯曲挠度的22%以上,应予以重视.
Based on the bending shear flow of thin-walled box girder,the paper analyzes the stress-strain relationship of the box girder.Combined with the elementary beam theory,the reasonable shear parameters for thin-walled box girders are derived so that the calculation of shear additional deflection of box girder web plate is simplified.By integrating the shear additional curvature with the energy variation principle,the web shear additional deflection and the deflection formula considering the effect of whole cross-section shear are obtained.The main factors affecting the deflection of flange plate and web plate are studied by comparing the additional shear deflection with the bending deflection so the model example with ANSYS software is established.The results show that the deflection obtained from the calculation formula in this paper is in good agreement with the calculation results from ANSYS software.When the width-span ratio and the depth-span ratio are relatively large,the shear additional deflection in mid-span section will be above 24% of the bending deflection when the simply supported beam is subjected to uniformly distributed load.
Based on the bending shear flow of thin-walled box girder,the paper analyzes the stress-strain relationship of the box girder.Combined with the elementary beam theory,the reasonable shear parameters for thin-walled box girders are derived so that the calculation of shear additional deflection of box girder web plate is simplified.By integrating the shear additional curvature with the energy variation principle,the web shear additional deflection and the deflection formula considering the effect of whole cross-section shear are obtained.The main factors affecting the deflection of flange plate and web plate are studied by comparing the additional shear deflection with the bending deflection so the model example with ANSYS software is established.The results show that the deflection obtained from the calculation formula in this paper is in good agreement with the calculation results from ANSYS software.When the width-span ratio and the depth-span ratio are relatively large,the shear additional deflection in mid-span section will be above 24% of the bending deflection when the simply supported beam is subjected to uniformly distributed load.
引文
[1] REISSNER E.Analysis of shear lag in box beams by the principle of the minimum potential energy[J].Quarterly of Applied Mathematics,1946,4(3):268-278.
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[3] ZHOU S J.Shear lag analysis in prestressed concrete box girders[J].Journal of Bridge Engineering,ASCE,2011,16(4):500-512.
[4] ZHANG Y H.Improved finite-segment method for analyzing shear lag effect in thin-walled box girders[J].Journal of Structural Engineering,ASCE,2014,138(10):1279-1284.
[5] 郭金琼.箱形梁设计理论[M].2版.北京:人民交通出版社,2008.
[6] 吴亚平.复合材料薄壁箱梁的剪滞剪切效应分析[J].土木工程学报,1996,29(4):31-38.
[7] 刘世忠,吴亚平,夏旻,等.薄壁箱梁剪力滞剪切变形双重效应分析的矩阵方法[J].工程力学,2001,18(4):140-144.
[8] 冀伟,刘世忠.波形钢腹板简支箱梁竖向频率的影响因素分析[J].振动、测试与诊断,2013,33(6):1039-1043.
[9] 冀伟,刘世忠,蔺鹏臻.波形钢腹板组合箱梁振动频率分析与试验[J].中国公路学报,2013,26(5):102-107.
[10] 周茂定,李丽园,张元海.考虑剪切变形时薄壁箱梁的挠曲分析[J].工程力学,2015,32(10):138-144.
[11] 周茂定,李丽园,张元海.薄壁箱梁的剪力滞翘曲位移函数研究[J].中国公路学报,2015,28(6):67-73.
[12] 张元海.箱形梁桥剪力滞效应及温度效应理论研究及其应用[D].成都:西南交通大学,2008.
[13] 罗旗帜.薄壁箱形梁剪力滞计算的梁段有限元法[J].湖南大学学报,1991,18(2):33-38.
[2] 罗旗帜.变截面多跨箱梁桥剪滞效应分析[J].中国公路学报,1998,11(1):63-70.
[3] ZHOU S J.Shear lag analysis in prestressed concrete box girders[J].Journal of Bridge Engineering,ASCE,2011,16(4):500-512.
[4] ZHANG Y H.Improved finite-segment method for analyzing shear lag effect in thin-walled box girders[J].Journal of Structural Engineering,ASCE,2014,138(10):1279-1284.
[5] 郭金琼.箱形梁设计理论[M].2版.北京:人民交通出版社,2008.
[6] 吴亚平.复合材料薄壁箱梁的剪滞剪切效应分析[J].土木工程学报,1996,29(4):31-38.
[7] 刘世忠,吴亚平,夏旻,等.薄壁箱梁剪力滞剪切变形双重效应分析的矩阵方法[J].工程力学,2001,18(4):140-144.
[8] 冀伟,刘世忠.波形钢腹板简支箱梁竖向频率的影响因素分析[J].振动、测试与诊断,2013,33(6):1039-1043.
[9] 冀伟,刘世忠,蔺鹏臻.波形钢腹板组合箱梁振动频率分析与试验[J].中国公路学报,2013,26(5):102-107.
[10] 周茂定,李丽园,张元海.考虑剪切变形时薄壁箱梁的挠曲分析[J].工程力学,2015,32(10):138-144.
[11] 周茂定,李丽园,张元海.薄壁箱梁的剪力滞翘曲位移函数研究[J].中国公路学报,2015,28(6):67-73.
[12] 张元海.箱形梁桥剪力滞效应及温度效应理论研究及其应用[D].成都:西南交通大学,2008.
[13] 罗旗帜.薄壁箱形梁剪力滞计算的梁段有限元法[J].湖南大学学报,1991,18(2):33-38.