断面与空钉对压板连接治疗管状骨骨折稳定性的分析

目的研究断面与空钉对压板连接治疗管状骨骨折稳定性的差异,为压板连接治疗管状骨骨折适应证的选择、接骨板的安放及后续治疗提供依据。方法将新鲜人体胫骨与长轴成45°角截骨,制作单斜面、双斜面、三斜面3种骨折模型,采用AO固定技术进行压板连接固定骨折,骨折两端至少各有3个螺钉固定。测量2 N、5 N作用力下骨折处加压、扭转、弯曲状况下的应变,对应变数据进行综合分析。结果不空钉情况下2 N、5 N加压、扭转、弯曲情况下应变(y)与断面变量(μ)关系分别如下:y2=25.6-3.5μ,y2=-63.8-11μ,y2=75.6-2.5μ,y5=44.6-0.5μ,y5=-413-5μ,y5=104.3+5.5μ。加压、扭转、弯曲情况下应变(y)与空钉变量(μ)关系分别如下:y2=11.6+26.1μ,y2=-112.9-100.4μ,y2=66.4+29.6μ,y5=35.9+61.4μ,y5=-423.9-107.4μ,y5=125.5+99μ。结论本实验表明压板连接治疗管状骨骨折稳定性受骨折断面多少的影响很小。空钉使压板连接治疗骨折的稳定性明显下降,空钉越多稳定性越差,空钉对稳定性的影响成线性变化。

1420铝锂合金异种板压印接头力学性能的研究

为了研究1420铝锂合金(1420)与异种材料的压印连接能力,选取TA1合金板、镀锌钢板和H62铜合金板与1420进行异种压印连接试验。对三组接头进行拉伸-剪切试验,得到三组接头的载荷-位移曲线。结果表明:TA1-1420接头的镶嵌量最大为0.2 mm,H62-1420接头的颈部厚度最小为0.34 mm;TA1-1420、H62-1420接头在拉伸-剪切试验中的最大载荷分别为4618.729、3119.3 N;TA1-1420、H62-1420接头的平均能量吸收值分别为9.84、3.865 J。

整机互联中挠性传输载体接口连接技术研究

研究了2种实现挠性传输载体接口的连接技术,即插针连接和压板连接,并分别对2种连接方式进行了有限元建模和可靠性分析,对压板连接还进行了电接触特性分析,通过工艺试验验证了2种连接方式的可行性。

锡盟±800千伏换流站搬运轨道工艺技术

作为运输换流变的通道,搬运轨道的施工工艺有着极高的要求。锡盟换流站工程地处我国高纬度高寒地区,冬夏季温差能达到80℃,温度变化大,钢材容易产生纵向形变。如何让搬运轨道自由伸缩,而不会对周围混凝土产生影响,是在该地区设计和建造换流变搬运轨道首先应该考虑并采取措施予以控制的问题,措施采取得当与否对搬运轨道及广场使用功能、观感质量、耐久性等都将产生重要影响。通过前期策划、设计、建设、施工等多方努力,锡盟±800千伏换流站搬运轨道在高寒等较为不利的建设条件下取得了较好的建设效果。本文对锡盟±800千伏换流站搬运轨道工艺技术进行了介绍,总结了锡盟站换流变搬运轨道技术创新及亮点,对于积累特高压换流站工程建设经验以及在高寒地区换流变搬运轨道等均具有重要借鉴和指导意义。

Failure behavior and mechanical properties of novel dieless clinched joints with different sheet thickness ratios

As one of the advanced and efficient means of joining,the clinching process is capable of joining sheets with different materials or different sheet thicknesses.In this article,a novel modified clinching process,i.e.,the dieless clinching process,was executed to join AA6061 aluminum alloy with sheet thicknesses of 1.5,2.0,2.5 and 3.0 mm according to different sheet stack-ups.The geometrical characteristics,microhardness distribution,failure behavior,static strength,absorbed energy and instantaneous stiffness of the novel dieless joint were gotten and investigated.The results indicated that the sheet thickness ratio has a notable effect on the failure behavior and mechanical properties of the novel dieless clinched joint,and a relatively large sheet thickness ratio can improve the joint performance when joining sheets with different sheet thicknesses.

换流变搬运轨道组装式地脚螺栓的研究与应用

换流变搬运轨道普遍采用现场焊接连接,针对北方寒冷地区出现钢轨及焊缝脆断的事故现象,对焊接连接方式进行理论计算并分析其适用性,通过压板式固定方式解决了轨道与轨道基础变形不协调的问题,对压板式换流变轨道固定技术进行优化,有效解决地脚螺栓在施工作业期间影响施工的问题,对于后期同类工程有着良好的借鉴价值。

Control of Vortex Shedding and Drag Reduction through Dual Splitter Plates Attached to a Square Cylinder

In this paper we have made a numerical study on the control of vortex shedding and drag reduction of a cylinder by attaching thin splitter plates. The wake structure of the cylinder of square cross-section with attached splitter plates is analyzed for a range of Reynolds number, based on the incident stream and height of the cylinder, in the laminar range. The Navier-Stokes equations governing the flow are solved by the control volume method over a staggered grid arrangement. We have used the semi-implicit method for pressure-linked equation （SIMPLE） algorithm for computation. Our results show that the presence of a splitter plate upstream of the cylinder reduces the drag, but it has a small impact on the vortex shedding frequency when the plate length is beyond 1.5 time the height of the cylinder. The presence of a downstream splitter plate dampens the vortex shedding frequency. The entrainment of fluid into the inner side of the separated shear layers is obstructed by the downstream splitter plate. Our results suggest that by attaching in-line splitter plates both upstream and downstream of the cylinder, the vortex shedding can be suppressed, as well as a reduction in drag be obtained. We made a parametric study to determine the optimal length of these splitter plates so as to achieve low drag and low vortex shedding frequency.

三段电源进线间联锁与解锁的实现方法

介绍三段电源进线间采用断路器辅助触点实现联锁及采用连接压板(或转换开关)实现解锁的方法。