Determination of non - linear buckling load for simple supported beam with bounded initial imperfection 不確定初缺陷簡(jiǎn)支梁非線性屈曲載荷的確定
The analysis of creep buckling of compressed column with initial imperfection and torsional elastic restraint 具初始缺陷兩端扭轉(zhuǎn)彈性約束壓桿的蠕變屈曲分析
According to the nonlinear governing equations of the large deflection plate theory , the ultimate strength formulations of the plate elements under combined loads are developed by taking into account the effects of initial imperfections 并考慮初始缺陷對(duì)極限強(qiáng)度的影響; ?按照ccs “油船結(jié)構(gòu)直接計(jì)算分析指南” ( 2004 )對(duì)110 , 000dwt原油船進(jìn)行有限元直接計(jì)算。
In this paper , through the overall stability analysis , the flexion eigenvalue , the nonlinear overall stability factor of the perfect structure and the nonlinear overall stability factor considering the initial imperfection of the different cable form projects and the relevant single - layer spherical latticed shell were compared ; the effect of different cable form projects to the structural overall stability was obtained 本文對(duì)選定的三個(gè)布索方案進(jìn)行了整體穩(wěn)定分析,比較了各方案的屈曲特征值、完善結(jié)構(gòu)的非線性整體穩(wěn)定系數(shù)和考慮初始缺陷的非線性整體穩(wěn)定系數(shù),并和相應(yīng)單層球面網(wǎng)殼做了對(duì)比,得到了布索圈數(shù)對(duì)結(jié)構(gòu)整體穩(wěn)定性能的影響。
An elastic - plastic and geometrically nonlinear finite element method is developed to analyze ultimate strength of h - shape steel columns under axial compressive loading . initial imperfections including residual stress due to hot - rolled and initial overall deflections of columns are considered . an experiment study of 21 h - shape steel columns with slenderness parameter of ranging from 40 to 120 is conducted to verify the theory results 本文通過(guò)彈塑性和幾何非線性的有限單元法理論分析,在長(zhǎng)細(xì)比范圍在40 ? 120的21根國(guó)產(chǎn)h型鋼軸心受壓柱的承載力試驗(yàn)中進(jìn)一步證實(shí)了這一理論的合理性和有效性。
The buckling and ultimate strength of ship plating normally depend on a variety of influential factors , namely geometric / material properties , loading characteristics , initial imperfections ( i . e . initial deflections and residual stresses ) , boundary conditions and corrosion , fatigue cracking 船體板的屈曲和極限強(qiáng)度取決于很多影響因素,主要有:板的幾何尺寸、材料特性、載荷特征、初始缺陷(如初始變形和焊接殘余應(yīng)力) 、邊界條件以及腐蝕的影響、疲勞裂紋等。
The influence of geometric nonlinear to the structures ’ stability is discussed , and the response of the structures with initial imperfection is analyzed by the consistent modal method . the characteristic of endogenetic force of the cylindrical latticed domes and some advice for the design are offered in the conclusion 深入討論了幾何非線性對(duì)柱面網(wǎng)殼和柱面組合網(wǎng)殼穩(wěn)定性的影響;最后采用一致模態(tài)法對(duì)結(jié)構(gòu)的幾何缺陷敏感性進(jìn)行分析,得出了柱面網(wǎng)殼和柱面組合網(wǎng)殼結(jié)構(gòu)的受力特點(diǎn)和在設(shè)計(jì)中應(yīng)注意的問(wèn)題。
In the hogging condition , double bottom and the side shell remain the ultimate bucking strength , deck and upperwing tank remain the yield stress , and the other parts keep elasticity . then the key to calculate the ultimate strength of ship hull girders is to ascertain the ultimate bucking strength of the stiffened panels . in this regard , the developed formulation is designed to be more sophisticated than previous simplified theoretical method for calculating the ultimate strength of stiffened panels under combined in - plane bending and lateral pressure . fabricatio n - related initial imperfections ( initial deflections and residual stresses ) are included in the panel ultimate strength calculation as parameters of influence . all possible collapse modes involed in collapse of stiffened panels , including overall buckling collapse , column or beam - column type collapse , tripping of stiffeners and local bukling of stiffened web are considered 確定了船體梁整體破壞時(shí)的剖面應(yīng)力分布之后,關(guān)鍵在于確定板架的極限屈曲強(qiáng)度。本文充分考慮了在縱向彎曲、橫向壓力作用下加筋板可能發(fā)生的幾種破壞模式,即板架的整體屈曲破壞、梁柱形式的破壞、筋的側(cè)傾、腹板的屈曲并同時(shí)考慮了初始焊接殘余應(yīng)力、初撓度的影響,使其更精確的計(jì)算加筋板的屈曲強(qiáng)度。對(duì)于加筋板中加強(qiáng)筋腹板的局部屈曲,采用解析法推導(dǎo)出筋的腹板的撓度方程及其邊界條件,求解相應(yīng)的方程,從而計(jì)算出腹板的局部屈曲應(yīng)力。