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ULTIMATE BEARING CAPACITY OF THIN-WALLED CURVED BEAMS
薄壁曲梁的稳定极限承载力

WEI Demin,CHEN Yuqing,
魏德敏
,陈宇清

力学与实践 , 2006,
Abstract: The ultimate bearing capacity of curved beams is related with the bending-torsion strength and the stability. With elastic-plastic deformation, the bending stress and the torsion stress are not linear with respect to the strain, so the problem will be more complicated. In this paper, using different formulae of the ultimate capacity of curved beams, a regression model is obtained. Through the nonlinear regression Calculation for a lot of computational results obtained by using the finite element method, a simplified and useful calculation formula is proposed, which can be used in the practical design of the curved beams.
NONLINEAR BUCKLING OF THE OPEN THIN-WALLED CURVED BEAMS
开口薄壁曲梁的非线性屈曲

WEI Demin,JIANG Bo,
魏德敏
,江波

力学与实践 , 2007,
Abstract: The stability of thin-walled structures is an important problem in civil engineering.In this paper,the nonlinear elastic buckling of the open thin-walled curved-beam is analyzed by using the finite element method. Through the nonlinear regression computation for a great number of Finite-Element results,a practical and simple formula is obtained,which can be used to estimate the ultimate bearing capacity of the open thin-walled curved beams.
拱形屋面温室纵向抗风分析中的曲梁刚度矩阵模型
Curved beam stiffness matrix model for the longitudinal wind resistance analysis of arch roof greenhouse
 [PDF]

郭韦佟,朱丹,宓林,蒋秀根
- , 2017,
Abstract: 研究拱形温室纵向抗风分析中的屋面拱结构。考虑弯扭耦合的影响,在对其几何方程、平衡方程、物理方程分析的基础上,建立了曲梁扭转角和弯曲挠度的控制方程;求得了用基函数向量以及积分常数向量表达的曲梁扭转角和弯曲挠度的解析解;根据位移边界条件,得到了位移系数;根据曲梁内力方程,建立了以矩阵形式表达的刚度平衡方程;经矩阵变换得到了曲梁弯扭分析的刚度矩阵模型以及等效节点力向量。本模型基于梁的刚度平衡方程,采用了精确的解析解,以矩阵形式表达了梁节点位移与节点力之间的关系,利用该模型,可对拱形温室的纵向抗风性能进行分析。
In order to study roof arch structure in the longitudinal wind resistance analysis of arched greenhouse,its torsion angle and bending deflection control equation considering bending-torsion coupling were developed based on the geometric equations,equilibrium equations and physics equations of curved beam.The analytical solutions of torsion angle and bending deflection expressed by primary function vector and integration constant were derived.The displacement coefficient was then obtained according to displacement boundary condition,and the stiffness equilibrium equation in matrix was established in line with equations of internal forces.After matrix transformation,stiffness matrix model and equivalent nodal force vector for the bending-torsion coupling analysis of curved beam were achieved.The model was constructed based on the stiffness equilibrium equation and accurate analytical solution.Nodal displacement and force were expressed in matrix according to this model.By using this model,the longitudinal wind resistant performance of arch greenhouse could be analyzed.
单索面曲梁悬索人行桥主缆线形分析
Cable shape analysis of curved suspension footbridge with single cable plane
 [PDF]

李立斌,王立彬,李建慧
LI Libin
, WANG Libin, LI Jianhui

- , 2017,
Abstract: 提出一种非线性有限元与数值计算结合的迭代法,并拓展大型软件迈达斯悬索桥分析功能,实现单索面曲梁悬索桥空间主缆的迭代找形计算。该方法以刚性支承连续曲梁竖向支座反力控制主缆立面垂度为主,以吊索倾斜角度计算吊索横向力和轴向力控制主缆横向垂度为辅,通过迭代吊索力大小和角度实现主缆找形,最终建立单索面曲梁悬索桥成桥状态三维空间有限元模型。计算结果表明:成桥状态主缆线形顺滑,塔、主缆、吊索和主梁空间布置姿态合理,吊索内力分布均匀合理,从而验证了迭代方法的正确性,为这一复杂桥型的设计分析提供参考。
A non-linear finite element iteration method combined with numerical calculation was proposed and the suspension bridge analysis function of Midas/Civil software was extended to fulfill the main cable shape-finding analysis. The rigid roller reactions in a curved beam bridges were obtained and used as reference values of the vertical component of the tension force of the hanger to control the sag in the vertical plane. And simultaneously, the lateral force was determined by adjusting trigonometric angular relation between the hangers and main cable in each iteration to control the horizontal sag of main cable. The iteration was not stopped until the convergence was obtained. The three dimensional space finite element model of the single cable plane curved suspension bridge was finally established. The calculation results show that the main cable shape is smooth. The tower, main cable and hanger are rationally arranged and the internal force of the hanger is evenly distributed. All of these results verify the correctness of the iterative method and provide a reference for the design and analysis of these complicated bridges
Silicon Force Sensor with Cross Beams
硅十字梁单块力传感器

Wang Yan/,
王言
,王毕南,晋琦,鲍敏杭

半导体学报 , 1990,
Abstract: An analysis of sensitivity is presented for a silicon force sensor with cross beams.Forcesensors with high sensitivity,small drift to tempreture and low cost can be fabricated by usingthis kind of structure.The sensors for four different ranges are fabricated under the guide ofthe analysis.The highest sensitivity of the sensois is approximately 340 mv/10g. It is suitablefor the measement of weak force, and it also has a special structure to resist over range force.
功能梯度变曲率曲梁的几何非线性模型及其数值解
GEOMETRICALLY NONLINEAR MODEL AND NUMERICAL SIMULATION OF FUNCTIONALLY GRADED VARIABLE CURVATURE CURVED BEAM
 [PDF]

万泽青 李世荣
- , 2015,
Abstract: 摘要 基于弹性曲梁平面问题的精确几何非线性理论,建立了功能梯度变曲率曲梁在机械和热载荷共同作用下的无量纲控制方程和边界条件,其中基本未知量均被表示为变形前的轴线坐标的函数。以椭圆弧曲梁为例,采用打靶法求解非线性常微分方程的两点边值问题,获得了两端固定功能梯度椭圆弧曲梁在横向非均匀升温下的热弯曲变形数值解,分析了材料梯度指数、温度参数、结构几何参数等对曲梁受力及变形的影响
多孔功能梯度梁的热-力耦合屈曲行为
Thermal-mechanical coupling buckling analysis of porous functionally graded beams
 [PDF]

苏盛开,黄怀纬
- , 2017, DOI: 10.13801/j.cnki.fhclxb.20170320.007
Abstract: 采用经典欧拉梁理论和高阶三角剪切变形理论,研究了多孔功能梯度梁的热-力耦合屈曲行为。分析中考虑了材料物性与温度的相关性,采用含孔隙率的Voight混合模型描述了多孔功能梯度的材料属性。利用迭代算法求解结构在均匀、线性和非线性温升(考虑热传导效应)下的热-力耦合屈曲临界温度,讨论了材料非均匀参数、孔隙率和长细比等参数对屈曲临界温度的影响。ABAQUS数值模拟结果和文献对比结果验证了理论的可靠性,同时表明高阶剪切变形理论较经典欧拉梁理论精确。结果表明,功能梯度材料梁的热屈曲分析必须考虑物性与温度的相关性,否则可能高估热屈曲临界温度10%~30%;随着孔隙率增大,材料的等效弹性模量减少,即结构刚度有所弱化,但屈曲临界温度反而大大增高。 The thermal-mechanical coupling buckling behavior of simply supported porous functionally graded beams was studied by classical Euler beam theory and high-order sinusoidal shear deformation theory. The correlation between material properties and temperature was considered, and the material properties of the porous functional graded beams were described by modified Voight mixture rule with porosity. The iterative algorithm was used to solve the critical thermal-mechanical coupling buckling temperature of the porous functionally graded beams under uniform, linear and nonlinear temperature rise (considering the heat conduction effect). And the influence of the parameters such as gradient distribution index, porosity and slenderness ratio on the critical buckling temperature were discussed. By comparing the results of ABAQUS and the literature, the theory is proved to be reliable, and the high-order sinusoidal shear deformation theory can obtain more accurate results than the classical Euler beam theory. The results show that in the analysis of the thermal buckling of functionally graded materials, the temperature dependence of material properties must be taken into account. Otherwise, the critical buckling temperature may be over-estimated by 10%-30%. As the porosity of the material increases, the equivalent elastic modulus of the functionally graded material will decrease, namely the structural stiffness will be weakened, while the critical buckling temperature of the structure will increase greatly. 国家自然科学基金(11402093);机械结构强度与振动国家重点实验室开放课题(SV2016-KF-08);广州市科技计划项目(201607010282)
薄壁曲线箱梁剪滞翘曲位移模式研究 Shear lag warping displacement mode research of thin-walled curved box girder  [PDF]
卢海林,蔡恒,黄民水,杨宏印
- , 2019,
Abstract: 为了寻找精度较高的剪力滞翘曲位移模式,分别假设曲线箱梁剪力滞翘曲位移函数按抛物线系列、余弦函数、指数函数、悬链线分布,综合运用能量变分法和Hamilton原理推导出曲线箱梁在各种剪力滞翘位移模式下的振动控制微分方程,通过假设位移场函数,由Galerkin法对曲线箱梁1阶竖向弯曲振动基频进行了求解,并获得了显示解.数值分析算例的结果表明:剪力滞翘曲位移模式对自振频率影响较小,箱梁翼板剪力滞翘曲位移函数选用2次抛物线和悬链线精度较高,能够较好地反映曲线箱梁空间受力性能;理论计算值与ANSYS板壳单元数值结果相比较,误差仅为0.57%,吻合良好,验证了理论推导的正确性与可靠性
键槽梁底筋锚入式预制梁柱连接恢复力模型
Restoring force model of precast beam-column connections incorporating beams with grooves and anchored bottom longitudinal bars
 [PDF]

管东芝,郭正兴,杨辉,杨森
- , 2018, DOI: 10.3969/j.issn.1001-0505.2018.05.007
Abstract: 为提高建造效率并有效保证结构性能,对2种键槽梁底筋锚入式预制梁柱连接(锚固与附加钢筋搭接混合连接和部分高强筋预制装配式框架梁柱连接)进行了研究分析.针对节点核心区较强的键槽梁底筋锚入式预制梁柱连接特点,提出了强度和变形计算方法,构建了三折线骨架曲线理论模型.通过线性拟合方法得出试验滞回曲线各阶段曲线刚度值,并拟合试件在低周反复荷载作用下各阶段刚度与加载位移角的关系,进而形成恢复力模型.计算结果表明,三折线理论骨架曲线与试验结果较为接近.建立的恢复力模型计算结果与试验滞回曲线吻合较好,反映了键槽梁底筋锚入式预制梁柱连接各阶段的受力特点,为弹塑性分析和抗震设计提供了理论依据.
In order to improve construction efficiency and ensure structural performance, two precast connections, including the precast connection combining anchored reinforcing bars and lap-spliced additional reinforcing bars and the precast concrete beam-to-column connection partially reinforced with high-strength rebars, are studied. Aiming at the precast connections incorporating beams with grooves and anchored bottom longitudinal bars with strong beam-to-column joints, the calculation methods for the strength and the deformation are proposed. The tribble linear line model is built. The stiffness of hysteresis loops at different stages is obtained by linear fitting, and the relationship of the stiffness and the loaded drift is established by fitting. Then, the restoring force model is built. The results show that the skeleton curves of the tribble linear line model are close to the experimental results of specimens. The established restoring force model can simulate the experimental hysteresis curves, reflecting the characteristics of the precast beam-column connections incorporating beams with grooves and anchored bottom longitudinal bars at different loaded stages. It provides a theoretical basis for elastic-plastic analysis and seismic design
曲梁的剪应力  [PDF]
熊翼翔
力学与实践 , 1992, DOI: 10.6052/1000-0992-1992-102
Abstract: 材料力学中推导了曲梁的正应力公式,对于剪应力,通常不予考虑,或者采用直梁的剪应力公式.文献[1]讨论了曲梁的剪应力,但该书的公式是有缺陷的.本文仍用材料力学方法推导曲梁的剪应力公式,所得结果,形式简单,便于与直梁沟通.最后,对矩形
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