碳纤维加固建筑夹芯板的挠度及承载力分析

采用有限元软件ANSYS模拟计算,通过修正剪力分配系数,主要对比研究普通夹芯板和碳纤维加固夹芯板的挠度计算公式和受弯承载力,为以后的设计工作提供了理论基础。     

弹性支承细长销轴的强度计算及工程应用

考虑销轴的弹性支承对销轴的强度分析十分必要,针对该问题给出了一种精确的销轴强度计算公式。公式在经典的梁理论基础之上考虑了弹性支座边界条件,并对比传统的刚性支承和简支工况下的强度分析公式,讨论了工程中销轴强度分析的精度问题。对实际工程应用中的细长弹性支承销轴进行挠度分析,同时在ANSYS中建立模型,采用有限元法计算销轴的挠度。通过对比理论公式和有限元方法的计算结果,证明了本文强度计算公式的正确性,并说明其工程应用。     

弹性支承细长销轴的强度计算及工程应用

考虑销轴的弹性支承对销轴的强度分析十分必要，针对该问题给出了一种精确的销轴强度计算公式。公式在经典的梁理论基础之上考虑了弹性支座边界条件，并对比传统的刚性支承和简支工况下的强度分析公式，讨论了工程中销轴强度分析的精度问题。对实际工程应用中的细长弹性支承销轴进行挠度分析，同时在ANSYS中建立模型，采用有限元法计算销轴的挠度。通过对比理论公式和有限元方法的计算结果，证明了本文强度计算公式的正确性，并说明其工程应用。     

现浇空心板的正交异性板理论分析方法的研究

在既有研究理论分析的基础上,考虑到现浇空心板周边暗梁及实心部分板的作用,基于等效系统法原理进行了现浇空心板两个方向的弹性抗弯主刚度修正,并将修正后的抗弯刚度公式应用到现浇空心板挠度和弯矩理论计算中.结合四边简支空心板算例,运用ANSYS有限元分析软件,对该修正方法分析结果精度进行了检验.结论表明,经刚度修正后的理论计算公式可满足工程应用要求.     

等效肋板法计算CS板受弯弹性变形

随着新型材料的广泛应用,对其受力性能的研究逐渐被重视。CS夹芯板广泛应用于建筑物的楼板和屋面板,其受弯变形能力一直是研究的重点。本文结合以往研究成果,通过理论推导和有限元分析得出了CS板受弯弹性变形的简化计算公式,经验证精度符合工程要求且计算方法简单,可为工程借鉴。     

基于ABAQUS的石材幕墙双跨立柱抗弯强度与变形计算分析

文章通过石材幕墙规范计算公式算得某石材幕墙双跨布置的钢立柱在风荷载作用下的最大弯曲强度和挠度值,再通过ABAQUS有限元分析软件建立钢立柱的仿真分析模型,将规范公式的计算结果与ABAQUS有限元分析模型的计算结果进行对比,验证了采用ABAQUS有限元近似计算石材幕墙双跨布置的钢立柱抗弯强度和挠度方法是可行的,研究结果将为实际工程中大跨度石材幕墙立柱的计算分析提供一定的科学依据。     

复合材料梯形波纹夹芯板的挠度分析

考虑剪切变形的影响,研究了复合材料波纹夹芯板均布荷载下的挠度。将复合材料波纹夹芯板等效为等刚度等尺寸的均质板,应用初等梁理论计算了考虑剪切变形的波纹夹层板的挠度。作为一个算例,应用所建立的模型计算了波纹夹芯板悬臂梁结构在均布荷载下的挠度,与有限元模拟得到的结果进行比较,验证本文模型的可行性,并讨论了剪切变形对挠度的影响。     

集中荷载作用下钢-混凝土组合梁界面滑移及变形

报道了8榀集中荷载作用下钢-混凝土组合简支梁的滑移规律和变形的试验结果。利用Goodman弹性夹层假设,推导了钢-混凝土组合简支梁的界面滑移和挠度变形的理论计算公式。该理论公式既能描述组合梁的界面滑移规律,又可以计算界面滑移对组合梁变形挠度的影响。利用通用有限元软件对钢-混凝土组合梁的界面滑移与变形进行了非线性有限元分析,并将多项计算结果进行了比较。通过大量理论计算,探讨工程设计中合适的剪力连接度。本文所得的理论计算公式,将方便工程设计人员对钢-混凝土组合结构滑移和变形挠度进行计算,并为其极限承载力的有限元计算提供了理论基础。     

建筑用绝热金属面夹芯板抗弯承载力的统一理论和有限元分析

通过对夹芯板的理论研究,得到不同面材夹芯板抗弯承载力的统一表达形式,并引入剪力分配系数的概念,采用有限元方法对不同面材的夹芯板进行回归分析,得到其关于板厚和面板厚度的表达式.最后,将基于此设计公式的计算同不锈钢、秸秆、铝面各种夹芯板的试验值等进行比较,验证设计公式的可行性,从而将各种不同金属面夹芯板抗弯承载力的设计公式...     

等截面双T平板挠度计算方法及试验研究

现行预应力混凝土双T板分级加载挠度计算,因其截面惯性矩计算复杂导致计算困难,不利于建设工程现场使用,为此,通过简化双T板截面惯性矩计算公式,将其代入挠度计算公式中,并通过有限元分析方法和试验研究方法进行验证。以YTPb型双T平板为例,均布力作用下和集中力作用下的有限元分析结果与公式计算结果误差分别在0.46%～1.54%与0.69%～0.92%之间;现场试验挠度试验结果与公式计算结果误差在0.28%～2.56%之间,说明简化后的挠度计算程序结果与有限元分析结果和试验结果对比拟合较好。     

钢-轻骨料混凝土组合梁变形理论与试验研究

为研究钢─轻骨料混凝土组合梁变形机理，运用最小势能原理建立了不完全交互作用组合梁的变形微分方程及简支组合梁在常见荷载作用下的跨中变形计算公式，并通过试验进行论证，理论与试验结果吻合良好．     

关于吊车梁绝对最大挠度的几个公式

单台、双台吊车荷载移动作用下 ,吊车梁跨中截面最大挠度的计算公式以及对应的吊车荷载最不利位置的解析判别公式。叠加恒载 (如自重、集中荷载 )作用下跨中截面的挠度 ,可作为吊车梁绝对最大挠度的简化计算公式 ,为吊车梁设计中的刚度校核计算提供理论依据。     

Approximate analysis method for composite beams with partial interaction using Fourier series

This paper presents an alternate analysis method for calculating the deflection and internal forces for arbitrary boundary and loading conditions of composite beams with partial interaction. The internal axial force was approximated by the Fourier series to solve the governing equation of composite beam. Then, the coefficients of the Fourier series were determined using the Euler-Lagrange equation of minimizing a definite integral. An evaluation of the convergence and the accuracy for the proposed method in the determination of the deflection for four types of boundary conditions with four types of loading cases was made. The results were agreed with those obtained by other analytical methods. The displacement of the partial composite beam depends on the stiffness of shear connectors, boundary conditions and loading conditions.     

不同火灾工况下钢梁-钢管混凝土柱平面框架受火全过程分析

采用多尺度建模方法建立了考虑钢材高温蠕变的三层三跨钢梁-钢管混凝土柱平面框架火灾全过程热-力耦合数值模型,研究不同火灾工况下平面框架经历常温加载、恒载升温、降温和火灾后等不同受火阶段的力学性能。在与已有试验对比验证的基础上,分析了框架经历升温和降温后受火钢梁跨中挠度和受火柱顶轴向变形与升降温时间关系,计算了火灾后框架底层柱底水平荷载P-框架顶层水平位移Δ关系曲线。研究结果表明：钢材的高温蠕变是钢材在热力耦合作用下应变的一部分,计算过程中需要考虑其影响;钢梁在升温过程中由于高温膨胀对框架柱产生外推作用,而进入降温阶段后钢梁产生明显的收缩变形;框架底层三跨同时受火时钢梁跨中挠曲变形最大,受火初期柱顶轴向压缩变形小于膨胀变形;受火后框架水平承载力和初始刚度均随受火区域的增大呈下降趋势。     

Finite element investigation on deflection of cellular beams with various configurations

The effect of the cellular beam configuration on the deflection has been investigated by using the three-dimensional finite element analysis of 408 cellular beams. Cross-section dimension, beam slenderness, opening size and opening spacing are found to affect the stiffness of the analytical load-deflection curve. The parametric study of the FE stiffness and normalized stiffness is conducted. The stress distribution of the finite element (FE) model reveals the strut stress in the web-post contributes to the increasing deflection in addition to the regular bending deflection. The deformation of the web-post and the relative movement between the upper and lower tee-sections due to strut stress is the main reason of the additional deflection in the cellular beams. The effect of the strut stress is found to be significant for the deflection of the short-span beams but less for the long-span beams. To convert the theoretical bending deflection to be the overall deflection, the calibrating coefficient function is established by using the empirical study. The function is formulated in terms of the slenderness, spacing and cross section ratio. The deflection prediction is useful to check serviceability condition for the design purpose.     

夹层玻璃蜕变的可靠性分析

运用夹层玻璃板一阶剪切变形位移模式,建立了新的有限元格式。运用摄动随机有限元法,考虑PVB胶弹性模量的随机性,分析并计算了PVB胶老化后的夹层玻璃板的挠度最大值,得到其失效概率,进而对夹层玻璃板的工作性能进行了预测。     

Buckling and postbuckling investigations of imperfect curved stringer-stiffened composite shells. Part A: Experimental investigation and effective width evaluation

A box-like stringer-stiffened thin-walled CFRP structure was subjected to load cases well beyond the limits of local buckling. The development of the deflection pattern was recorded via optical means and analysed numerically. In addition, the structure was modelled and analysed using the MARC FE program in the nonlinear deflection range.

The geometrical imperfections of the test structure were recorded by mechanical scanning and optical methods and introduced into the mathematical model. For the perfect (‘ideal’) and the geometrically imperfect (‘real’) structural model, the results of the FE analyses were compared and used to judge the effect of geometric imperfections on the postbuckling behaviour of the structure.

The effective axial stiffness for the various postbuckling states was evaluated and related to analytical estimates of effective width values for orthotropic sheet-like panels.     

Experimental characterization and finite element analysis of inflated fabric beams

An airbeam is a high-strength fabric sleeve with a highly flexible internal bladder that can be used as a load-bearing beam or arch when inflated. Due to their fabric construction, airbeams are inherently thin-walled structures that are prone to local buckling. In this study, airbeams were tested in bending at different inflation pressures to quantify their load–deformation response and the effect of inflation pressure on response. Tension–torsion tests of the airbeam fabric were conducted to estimate the fabric shear modulus, and the bend test results were used in conjunction with Timoshenko beam theory to estimate the fabric elastic modulus. Three-dimensional membrane finite element (FE) models were then used to predict the beam load–deformation response given these moduli. The FE models successfully predicted localized fabric buckling and softening of load–deflection response. Comparison of FE model-predicted load–deflection response with beam theory shows that conventional beam theory is accurate prior to local buckling of the airbeam fabric. The FE model and test results indicate that the consideration of work done by pressure under deformation-induced volume changes may increase beam capacity beyond previously derived theoretical limiting values.     

钢筋混凝土受弯构件挠度计算方法综述分析

讨论了影响钢筋混凝土受弯构件短期挠度和长期挠度的主要因素,系统地阐述了国内外钢筋混凝土受弯构件挠度计算理论的研究现状,综述了受弯构件挠度计算方法。根据国内外对钢筋混凝土受弯构件挠度的试验研究成果,计算并分析了各种短期挠度和长期挠度计算方法的适用性。     

薄壁箱形截面钢柱稳定极限承载力的有限元数值模拟

基于薄板的弹塑性大挠度有限元理论,采用有限元方法在综合考虑几何缺陷和力学缺陷的基础上,建立模拟薄壁箱形截面钢柱稳定极限承载力的有限元模型,并将数值模拟结果与已知试验结果进行比较,证实有限元方法的有效性,为进一步研究提供依据。