防灾减灾工程学报
防災減災工程學報
방재감재공정학보
JOURNAL OF DISASTER PREVENTION AND MITIGATION ENGINEERING
2010年
1期
48-52
,共5页
张穿云%童小东%洪雪松%吴东红
張穿雲%童小東%洪雪鬆%吳東紅
장천운%동소동%홍설송%오동홍
ACI318-08规范%受弯构件%受压构件%林聪悟-直线法%强度降低系数%配筋量
ACI318-08規範%受彎構件%受壓構件%林聰悟-直線法%彊度降低繫數%配觔量
ACI318-08규범%수만구건%수압구건%림총오-직선법%강도강저계수%배근량
ACI318-08 Code%bending member%compressive member%Tsung-wu LIN linear method%strength reduction factor%reinforcement
首先,阐述了美国ACI318-08规范中钢筋混凝土受弯、受压构件的设计原理和基本假定.与我国混凝土结构设计规范不同,ACI318-08规范是根据构件的受力破坏形态来确定名义抗压和抗弯承载力的折减系数的,相对于延性破坏,脆性破坏构件的承载力折减较多.然后,由平衡条件、平截面假定及Newton迭代格式,推导出林聪悟-直线法的计算公式.编制程序实现该算法时,须根据最大、最小配筋率的规定对迭代区域进行限定;在确定P-M相关曲线上的拐点位置的基础上,实现中性轴高度在曲线上的分段迭代.通过在曲线拐点处设置微小增量及自动调整中性轴高度等方法,解决了程序计算时可能出现的迭代发散问题.算例表明,所编制程序的计算结果具有很高的精度.
首先,闡述瞭美國ACI318-08規範中鋼觔混凝土受彎、受壓構件的設計原理和基本假定.與我國混凝土結構設計規範不同,ACI318-08規範是根據構件的受力破壞形態來確定名義抗壓和抗彎承載力的摺減繫數的,相對于延性破壞,脆性破壞構件的承載力摺減較多.然後,由平衡條件、平截麵假定及Newton迭代格式,推導齣林聰悟-直線法的計算公式.編製程序實現該算法時,鬚根據最大、最小配觔率的規定對迭代區域進行限定;在確定P-M相關麯線上的枴點位置的基礎上,實現中性軸高度在麯線上的分段迭代.通過在麯線枴點處設置微小增量及自動調整中性軸高度等方法,解決瞭程序計算時可能齣現的迭代髮散問題.算例錶明,所編製程序的計算結果具有很高的精度.
수선,천술료미국ACI318-08규범중강근혼응토수만、수압구건적설계원리화기본가정.여아국혼응토결구설계규범불동,ACI318-08규범시근거구건적수력파배형태래학정명의항압화항만승재력적절감계수적,상대우연성파배,취성파배구건적승재력절감교다.연후,유평형조건、평절면가정급Newton질대격식,추도출림총오-직선법적계산공식.편제정서실현해산법시,수근거최대、최소배근솔적규정대질대구역진행한정;재학정P-M상관곡선상적괴점위치적기출상,실현중성축고도재곡선상적분단질대.통과재곡선괴점처설치미소증량급자동조정중성축고도등방법,해결료정서계산시가능출현적질대발산문제.산례표명,소편제정서적계산결과구유흔고적정도.
The paper firstly expounds the design principles and fundamental assumptions of flexural and compressive reinforced concrete members in Building Code Requirements for Structural Concrete (ACI318-08). Different from Chinese design code of concrete structures, ACI318-08 determines the reduction factor of nominal compressive and bending capacity according to the member' s stress failure mode. The degree of a member's capacity reduction in the brittle failures is greater than that in the ductile ones. Then a calcu-lation formula of Tsung-wu LIN linear method is proposed on the basis of the equilibrium condition, plane section assumption, and Newton's iterative method. In computer implementation of the algorithm for the formula, limitation of iterative region according to the maximal and minimal reinforcement ratio is neces-sary; in addition, the location of inflection points in P-M Relative Curves should be determined in order to realize the respective iteration of the neutral axis height in the curve. Through the establishment of small increment in curve' s inflection points as well as the automatic adjustment of the neutral axis height, the possible iterative divergence problem of Tsung-wu LIN linear method in computer programming is solved. The results show that numerical solutions from the computer program are of high precision.