共查询到20条相似文献，搜索用时 290 毫秒
1.
针对弹性支承的特点，利用结构分解及叠加原理，通过举例阐述了弹性支承下轴的强度与刚度的简例计算方法。 相似文献
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对中国混凝土结构耐久性设计规范( GB/T 50476-2008)和Eurocode中有关混凝土桥梁耐久性设计的相关条款进行了对比.对2种规范中关于结构所处环境等级的划分和混凝土最小保护层厚度和最低强度等级等相关规定做了比较和分析.并用数值计算方法对处于碳化和氯盐侵蚀环境(海洋环境和除冰盐环境)下的桥梁耐久性设计年限进... 相似文献
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在掌握了轴向拉仲(压缩)、圆轴扭转及梁的弯曲这三种基本变形的内力、应力、变形及强度和刚度计算后,我们将进一步学习以这三种基本变形为基础的组合变形,而为解决组合变形时的强度问题,就必须先掌握应力状态理论和强度理论。 相似文献
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介绍了卧式压力容器条形支座支承角度和壳体应力计算方法，用Ｃ语言编写了计算程序，并给出了一个设计实例的设计结果。 相似文献
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《现代教育技术》2019,(11):74-79
文章采取课堂视频分析法,以来自6个省市的9节中小学英语课程视频为研究对象,分析了平板电脑应用于中小学英语课堂教学中的主要功能,发现:每节课平板电脑各功能应用的平均时长为12分38秒,约占每节课时长(按50分钟计算)的1/4,可以有效避免长时间使用平板电脑对学生视力造成的负面影响;在9节中小学英语课程视频中,平板电脑各功能单独应用的次数从多到少依次为演示、检测、做题和拍录。基于此,文章概括了平板电脑应用于中小学英语课堂教学中的优势和不足,并针对管理部门、研发机构和英语教师三个群体分别提出了相应的建议,以期促进平板电脑与课堂教学的深度融合和常态应用、实现课堂教学的高效公平。 相似文献
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阐述了平板—异形柱结构的适用范围、结构选型、材料选择、截面尺寸的确定和结构的内力分析方法,在此基础上得出了平板—异形柱结构构件的配筋计算方法和配筋构造要求,以供设计人员参考。 相似文献
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三向应力圆的一种简单推导方法冯贤桂在材料力学和弹性力学课程中，分析空间应力状态时都要推导出三向应力圆方程。代表某一点任意斜截面下正应力和剪应力的点都位于以三个主应力所作的三向应力圆内。本文用一种比较简单的方法来进行推导。设已知某一点三个主应力为σ＿１... 相似文献
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备向同性材料的三个弹性常数E、G、μ之间存在着如下关系;G=E/(2(1+μ)) 材料力学教材中,一般采用平面应力状态下单元体的应力与应变之间的关系来验证上式。验证过程中要分析变形的几何关系。在教学中,为了使学生更好地掌握应力分析和应变分析以及二者之间的关系,可以用应力圆和应变圆来验证上述三个弹性常数之间的关系。 相似文献
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董月芬 《石家庄职业技术学院学报》2006,18(6):45-46,57
应用薄膜理论、第三强度理论探讨了内压作用下环壳内的应力和应力状态,对薄壁回转壳体的强度设计、计算壁厚进行了详细分析. 相似文献
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To analyze the effects of width and thickness of each composition element of mixed steel U-rib-stiffened plates on the welding residual stress distribution, the distribution of the U-rib and the plate residual stress was calculated using a simplified calculation method. The method involved welding the mixed steel U-rib-stiffened plates for a structure with different sizes and different strength ratios of U-rib to plate. Based on a welding residual stress numerical simulation method validated by the blind hole method test, the distribution law of the mixed steel U-rib stiffened plate was studied. The results showed that the change of plate width has little impact on the welding residual stress and that the ratio of the thicknesses of the plate to U-rib stiffeners, the thickness of the plate, and the thickness of the U-rib has a great influence on the distribution of the welding residual stress. The thickness of plate and steel strength also greatly influenced the distribution width of the residual tensile stress. While analyzing the compression capacity of U-rib-stiffened plates, the simplified distribution of welding residual stress was used. 相似文献
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以茅人杰提出的单向短纤维复合材料的模型为基础,得出单向短纤维复合材料轴向拉伸强度的计算方法．考虑到单向短纤维复合材料的横向拉伸强度、面内剪切强度,利用两对坐标轴间应力转换关系,导出单向纤维复合材料受任意方向拉伸时的应力;由无规高聚物材料分子链主轴和取向方向间夹角θ＝５４°４４′,利用一等价关系,最后导出随机取向短纤维复合材料的拉伸强度表达式． 相似文献
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依据HG/T 20582-2011《钢制化工容器强度计算规定》中第十二章的内容,采用CurveExpert对非圆法兰强度计算中的系数fA进行算法模拟。解决了非圆法兰自动强度计算过程中,由于查取fA函数图或表而造成的程序编制中断、操作不便的问题,提高了非圆形法兰强度的设计效率和准确性。 相似文献
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This paper proposes a theoretical method using finite element analysis （FEA） to calculate the plastic collapse loads of pressure vessels under internal pressure, and compares the analytical methods according to three criteria stated in the ASME Boiler Pressure Vessel Code. First, a finite element technique using the arc-length algorithm and the restart analysis is developed to conduct the plastic collapse analysis of vessels, which includes the material and geometry non-linear properties of vessels. Second, as the mechanical properties of vessels are assumed to be elastic-perfectly plastic, the limit load analysis is performed by employing the Newton-Raphson algorithm, while the limit pressure of vessels is obtained by the twice-elastic-slope method and the tangent intersection method respectively to avoid excessive deformation. Finally, the elastic stress analysis under working pressure is conducted and the stress strength of vessels is checked by sorting the stress results. The results are compared with those obtained by experiments and other existing models. This work provides a reference for the selection of the failure criteria and the calculation of the plastic collapse load. 相似文献
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将振动输送机主振弹簧的强度视为模糊变量，弹簧的剪切应力视为随机变量，运用模糊数学理论和方法，建立其模糊可靠度的设计计算方法，并对振动输送机主振弹簧的实例进行了计算分析。 相似文献
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A first order system model is proposed for simulating the influence of stress stimulation on fracture strength during fracture
healing. To validate the model, the diaphyses of bilateral tibiae in 70 New Zealand rabbits were osteotomized and fixed with
rigid plates and stress-relaxation plates, respectively. Stress shielding rate and ultimate bending strength of the healing
bone were measured at 2 to 48 weeks postoperatively. Ratios of stress stimulation and fracture strength of the healing bone
to those of intact bone were taken as the system input and output. The assumed first order system model can approximate the
experimental data on fracture strength from the input of stress stimulation over time, both for the rigid plate group and
the stress-relaxation plate group, with different system parameters of time constant and gain. The fitting curve indicates
that the effect of mechanical stimulus occurs mainly in late stages of healing. First order system can model the stress adaptation
process of fracture healing. This approach presents a simple bio-mathematical model of the relationship between stress stimulation
and fracture strength, and has the potential to optimize planning of functional exercises and conduct parametric studies.
Project (No. 39470698) supported by the National Natural Science Foundation of China 相似文献
17.
Behavior of axially loaded tubular X-joints using bolted connection: mechanical model and validation
Yong Chen Ji-yang Wang Yong Guo Guo-hui Shen Li-xian Yang Bin-nan Sun 《浙江大学学报(A卷英文版)》2013,14(12):880-889
X-joints are one of the fundamental joint configurations used in a wide range of transmission tubular structures. Experimental investigation of lbur tubular X-joints with bolted connection was conducted in this study, and it was found that the annular plate was the main yielding control member of such X-joints. Moreover, the portion outside the effective width of the chord member still had a restriction effect on the annular plate, which led to reducing the yielding strength of the joint, while the gusset plate could help to improve the yield strength capacity. In the current design code of steel structures, the contribution to the strength capacity of the gusset plate has not been taken into account. Therefore, based on some mechanical assumptions, a general mechanical model was proposed. After the introduction of the gusset plate strength capacity factor, the yield capacity simplified calculation method of such X-joints was derived. Through the analyses of such X-joints with various diameters and thicknesses, it was concluded that a simple mechanical model could predict test results very well and that the contribution of the gusset plate was also taken into account. 相似文献
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To figure out the distribution of temperature gradient along the girder height of steel-concrete composite box girder, combined with the mechanical characteristics of prestressed concrete composed box girder with corrugated steel webs, the calculation formulas of cross-sectional temperature stress along the span in a simply-supported beam bridge with composite section were derived under the conditions of static equilibrium and deformation compatibility of the beam element. The methods of calculating the maximum temperature stress value were discussed when the connectors are assumed rigid or flexible. Theoretical and numerical results indicate that the method proposed shows better precision for the calculation of temperature self-stress in both the top and the bottom surfaces of the box girder. Moreover, the regularity of temperature stress distribution at different locations along the girder span is that the largest axial force of the top or the bottom plate of the box girder is located in the midspan and spreads decreasingly until zero at both supported ends, and that the greatest longitudinal shear density in steel-concrete interface appears at both supported ends and then reduces gradually to zero in the midspan. 相似文献
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ALSHOAIBI Abdulnaser M HADI M.S.A ARIFFIN A.K. 《浙江大学学报(A卷英文版)》2007,8(2):228-236
INTRODUCTION The finite element method (FEM) has proved to be very well suited for the study of fracture mechanics. Nevertheless, modelling the propagation of a crack through a finite element mesh turns out to be difficult because of the modification of the mesh topology. Use of crack propagation laws based on stress inten-sity factor range is the most successful engineering application of fracture mechanics. The stress intensity factors are a very important parameter in fracture analys… 相似文献