兰州交通大学学报
蘭州交通大學學報
란주교통대학학보
JOURNAL OF LANZHOU JIAOTONG UNIVERSITY(Natural Sciences)
2014年
4期
72-75,88
,共5页
白昕%刘亮%胡玉茹%张元海
白昕%劉亮%鬍玉茹%張元海
백흔%류량%호옥여%장원해
薄壁箱梁%剪力滞效应%附加挠度%广义位移%广义力矩
薄壁箱樑%剪力滯效應%附加撓度%廣義位移%廣義力矩
박벽상량%전력체효응%부가뇨도%엄의위이%엄의력구
thin-walled box girder%shear lag effect%additional deflection%generalized displace-ment%generalized moment
与已有文献中采用的广义位移不同,选取剪力滞引起的附加挠度作为广义位移,在构造广义翘曲位移函数的基础上,提出了一种分析箱梁剪力滞的解析法.基于能量变分法建立控制微分方程,并导出了简支箱梁的附加挠度和广义力矩计算公式.通过对一个混凝土简支箱梁算例的计算表明,按本文方法计算的跨中截面应力与有限元法的结果很接近,从而验证了方法的正确性.研究结果表明,剪力滞引起的混凝土简支箱梁跨中截面的附加挠度很小,工程实践中可以忽略不计,但是,跨中截面的剪力滞翘曲应力达到初等梁应力的11.4%,工程实践中不能忽略.
與已有文獻中採用的廣義位移不同,選取剪力滯引起的附加撓度作為廣義位移,在構造廣義翹麯位移函數的基礎上,提齣瞭一種分析箱樑剪力滯的解析法.基于能量變分法建立控製微分方程,併導齣瞭簡支箱樑的附加撓度和廣義力矩計算公式.通過對一箇混凝土簡支箱樑算例的計算錶明,按本文方法計算的跨中截麵應力與有限元法的結果很接近,從而驗證瞭方法的正確性.研究結果錶明,剪力滯引起的混凝土簡支箱樑跨中截麵的附加撓度很小,工程實踐中可以忽略不計,但是,跨中截麵的剪力滯翹麯應力達到初等樑應力的11.4%,工程實踐中不能忽略.
여이유문헌중채용적엄의위이불동,선취전력체인기적부가뇨도작위엄의위이,재구조엄의교곡위이함수적기출상,제출료일충분석상량전력체적해석법.기우능량변분법건립공제미분방정,병도출료간지상량적부가뇨도화엄의력구계산공식.통과대일개혼응토간지상량산례적계산표명,안본문방법계산적과중절면응력여유한원법적결과흔접근,종이험증료방법적정학성.연구결과표명,전력체인기적혼응토간지상량과중절면적부가뇨도흔소,공정실천중가이홀략불계,단시,과중절면적전력체교곡응력체도초등량응력적11.4%,공정실천중불능홀략.
Differing from the generalized displacement used in existing references,the additional de-flection induced by shear lag is adopted as generalized displacement for analyzing shear lag of box girders.Based on the generalized warping displacement function defined,an analytic method for analyzing shear lag is proposed.The governing differential equation is established by applying en-ergy calculus and the formulas of the additional deflection and generalized moment for simply sup-ported box girder are derived.An example of simply supported concrete box girder is analyzed and the calculated stress results at mid-span cross section are very close to those by finite element method,validating the present analytic method.It is shown that the additional deflection at the mid-span cross section of the simply supported concrete box girder is very small and thus can be ignored in engineering practice.However,the shear lag warping stress at the mid-span cross sec-tion reaches 1 1 .4% of the ordinary beam stress,which should not be ignored in engineering prac-tice.