功能材料力-电耦合问题的几个基本解——(Ⅱ)悬臂梁梁端受轴向集中力作用

本文是本系列工作的第二部分 ,研究了功能材料悬臂梁梁端受轴向集中力作用的情况。采用半逆解法 ,分别求解了无体力悬臂梁、常体力悬臂梁以及密度梯度悬臂梁中的力 -电耦合问题 。

《钢筋混凝士基本构件配筋计算程序讲座》(七) 双向偏心受压构件正截面承载力简捷计算法

这一讲叙述的双向偏心受压构件正截面承载力简捷计算法,是根据蓝宗建同志提出来的方法,编制偏心受压构件正截面承载力计算机程序。符号说明:Nux轴向力作用于 x 轴。

评冯康、石钟慈的《弹性结构的数学理论》

有限元方法作为一种数值方法,其萌芽思想可以追溯到很早,十八世纪瑞士数学家、力学家欧拉就曾用与现代位移有限元方法相同的方法求解过杆在轴向力作用下的平衡问题。但是,赋予有限元方法一个严谨的数学基础和理论框架,还主要是在本世纪六十年代形成并进一步发展起来的。《弹性结构的数学理论》的作者之一冯康教授。

大螺距圆锥形螺旋弹簧应力与弹性位移的分析

本文对工业、民用、军事工程中常用的一种大螺距圆锥形螺旋弹簧的零件在轴向力作用下的受力进行分析,并用能量守恒原理导出大螺距圆锥形螺旋弹簧在轴向力作用下的应力与弹性位移计算公式τ_(na)x=16PR/πd^3(1+d/4R)cosαλ=2πnPR^3(cosα~2/RI_P+sin^2α/EI)

A Theoretical Analysis of the Bearing Performance of Vertically Loaded Large-Diameter Pipe Pile Groups

This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups.The interactions between group piles result in different bearing performance of both a single pile and pile groups.Considering the pile group effect and the skin friction from both outer and inner soils,an analytical solution is developed to calculate the settlement and axial force in large-diameter pipe pile groups.The analytical solution was verified by centrifuge and field testing results.An extensive parametric analysis was performed to study the bearing performance of the pipe pile groups.The results reveal that the axial forces in group piles are not the same.The larger the distance from central pile,the larger the axial force.The axial force in the central pile is the smallest,while that in corner piles is the largest.The axial force on the top of the corner piles decreases while that in the central pile increases with increasing of pile spacing and decreasing of pile length.The axial force in side piles varies little with the variations of pile spacing,pile length,and shear modulus of the soil and is approximately equal to the average load shared by one pile.For a pile group,the larger the pile length is,the larger the influence radius is.As a result,the pile group effect is more apparent for a larger pile length.The settlement of pile groups decreases with increasing of the pile number in the group and the shear modulus of the underlying soil.

Non-Darcy flow seepage characteristics of saturated broken rocks under compression with lateral constraint

Using an MTS816.03 test system and self-designed seepage apparatus, seepage tests of saturated broken rocks were conducted, and the influence of lithology, axial stress, grain size distribution and loading rate on seepage characteristics was analyzed. The results show that： （1） Under the same axial stress （12 MPa）, the permeability of different lithologic samples increases in the order： gangue 〈 mudstone 〈 sandstone 〈 limestone. The permeability of gangue is 3 magnitudes lower than that of limestone. The absolute value of the non-Darcy coefficient β increases in the order： limestone 〈 sandstone 〈 mudstone 〈 gangue. The non-Darcy coefficient β of limestone, which is positive, is 5 magnitudes lower than that of gangue. （2） With increasing axial stress, the permeability of saturated broken sandstone decreases, and the absolute value of the non-Darcy coefficient β increases. After the axial stress exceeds 12 MPa, the curves of permeability and non-Darcy coefficient β all tend to be stable. （3） With increasing Talbol power exponent, the permeability increases, and the absolute value of the non-Darcy coefficient β decreases. （4） With increasing loading, the permeability increases, and the absolute value of the non-Darcy coefficient β decreases. When the loading rate is 0.5 kN/s, the non-Darcy coefficient β is positive.

非轴向力下埋入式光纤传感器应变传递分析

利用剪滞法建立了当光纤光栅传感器的轴线和基体主应力的方向成一定角度时,光纤光栅传感器的测量应变与基体结构实际应变之间的关系,进而得出了光纤光栅传感器的平均应变传递率的一般公式。采用裸光纤光栅传感器进行实验,在倾斜角度α为30.72°时,实验所得的波长变化之比分别为:0.727,0.738,0.746;理论计算所得的波长变化之比为0.739,相对误差都在2%以内。同时分析了埋设角度偏差对测量结果的影响。研究结果表明,非轴向力作用下光纤光栅传感器的应变与结构基体应变之间的传递关系与其在轴向力作用下存在明显的区别,埋设角度的偏差会给测量结果造成一定的误差。