本文關(guān)鍵詞：基于裂縫分布特征的橋梁損傷評(píng)價(jià)與計(jì)算方法研究　出處：《河北工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 鋼筋混凝土 裂縫 損傷評(píng)價(jià) X-FEM理論 ABAQUS

【摘要】：鋼筋混凝土是目前橋梁中應(yīng)用最為廣泛的材料,但隨著運(yùn)營時(shí)間的不斷推移,在多種因素的影響下,既有鋼筋混凝土橋梁經(jīng)常會(huì)出現(xiàn)各種損傷,其中裂縫是最主要的表現(xiàn)形式之一。為確保結(jié)構(gòu)的安全性,對(duì)裂縫這一主要病害特征開展研究,繼而對(duì)結(jié)構(gòu)的損傷狀況和承載能力作出評(píng)價(jià)具有極為重要的理論價(jià)值和現(xiàn)實(shí)意義。本文首先歸納了鋼筋混凝土裂縫的分類及成因,介紹了X-FEM裂縫損傷擴(kuò)展有限元理論及在ABAQUS軟件中的應(yīng)用。而后以簡(jiǎn)支梁和連續(xù)梁為研究對(duì)象,在前人二維模型的基礎(chǔ)上,建立了更為真實(shí)的三維實(shí)體損傷模型,據(jù)此分別研究了受彎豎向裂縫、受剪斜裂縫、裂縫數(shù)量以及混凝土配筋量、鋼筋形狀、是否帶初始微裂縫等多種工況下結(jié)構(gòu)的損傷狀況和承載能力,獲得主要結(jié)論如下:(1)有無初始微裂縫的簡(jiǎn)支梁,在相同荷載作用下后期產(chǎn)生的裂縫在高度和寬度上較為相近,鋼筋應(yīng)力也無太大差異,說明有無初始微裂縫對(duì)結(jié)構(gòu)損傷影響較小。同時(shí)發(fā)現(xiàn),在三維模型中局部裂縫開裂位置處的鋼筋要比兩邊的鋼筋損傷要大,這一點(diǎn)在二維模型中無法體現(xiàn)。(2)相同簡(jiǎn)支梁在單條初始裂縫的情況下,以裂縫高度為指標(biāo)的無筋梁、少筋梁、適筋梁和超筋梁的損傷呈明顯遞減的趨勢(shì),且不配置鋼筋與配筋量較少時(shí),混凝土的損傷狀況均較為嚴(yán)重,而超筋梁存在發(fā)生突然破壞的潛在風(fēng)險(xiǎn)。多條裂縫的計(jì)算結(jié)果與單條裂縫一致。(3)在斜裂縫處,鋼筋彎起后與彎起前相比,其應(yīng)力值削減近一倍,同時(shí)裂縫長(zhǎng)度亦明顯縮減,說明在支座附近處將鋼筋彎起是一種降低結(jié)構(gòu)損傷、抑制斜裂縫擴(kuò)展的有效方法。(4)對(duì)相同載荷作用下的連續(xù)梁而言,相比僅正裂縫存在的情況,斜裂縫和正裂縫的同時(shí)出現(xiàn),由于梁內(nèi)部應(yīng)力的重新分布,正裂縫的開展反而相對(duì)緩慢,裂縫高度變低,受彎區(qū)的損傷亦減輕。
[Abstract]:Reinforced concrete bridge is currently the most widely used material for the application, but with the continued operation time, under the influence of various factors, existing reinforced concrete bridge will often appear all sorts of damage, crack is one of the most important form. In order to ensure the safety of the structure, to carry out research on the main diseases of crack then the characteristics, structural damage and bearing capacity evaluation has extremely important theoretical value and practical significance. This paper summarizes the classification and causes of concrete cracks, introduces the application of the extended finite element theory and ABAQUS software X-FEM. Then the crack damage of the simply supported beam and continuous beam as the research object, in the based on the two-dimensional model, a three-dimensional damage model is true, according to respectively study the flexural vertical cracks, shear crack, crack number and Reinforced concrete, reinforced with initial shape, whether micro cracks under conditions such as structural damage and bearing capacity, the main conclusions are as follows: (1) beams with no initial micro cracks, cracks in the later stage under the same load in height and width are similar, the steel stress is not so there is no big difference, that the initial micro cracks on the structure damage influence. At the same time, the reinforced local cracking position of 3D model than reinforced damage on both sides of the larger, this point in the 2D model can not reflect the. (2) the same beam in a single initial crack under the condition of the fracture height as an indicator of the beams, reinforced beam, reinforced Liang Hechao beam damage showed a decreasing trend, and the allocation of less reinforcement and reinforcement, damage of concrete are more serious, and there are sudden destruction over reinforced beam The potential risk of cracks. The calculation results are consistent with a single crack. (3) in the oblique cracks, bending up and bend than before, the stress value cut nearly doubled, while crack length is also significantly reduced, in the vicinity of the bearing steel bend is a structure for reducing loss injury, effective method to suppress the oblique crack propagation. (4) of the continuous beam under the same load, there is only compared to the cracks, cracks and cracks at the same time, due to the re distribution of internal stress of the beam, is the development of cracks but relatively slow crack height low, bending the injury was alleviated.

【學(xué)位授予單位】：河北工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U446

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本文編號(hào)：1396977