等效加劲截面及直接强度法计算

对试验截面按照惯性矩相等、截面宽度不变的原则进行了等效,以便更好的应用于实践,用直接强度法对等效加劲截面构件承载力进行了计算,通过与试验构件比较,得到等效结果比较理想的结论。

传统农居砌体抗剪性能试验研究

砖砌体结构是农村传统农居建筑的主要结构形式,如何精确评价其抗震能力具有重要的研究意义。目前既有传统农居中,20世纪80、90年代砖砌体结构仍是其重要的组成部分。为研究既有传统砖砌体结构的抗剪性能,首先对水泥砂浆、白灰砂浆、炉渣砂浆、黄泥砂浆4种典型砂浆开展抗压强度试验;然后对4种典型砂浆砌筑的砌体进行沿通缝抗剪强度试验,通过与传统老旧红砖砌体抗剪强度的平均值和公式值进行对比,对砌体抗剪强度计算公式进行修正后得到修正公式;最后对比修正值、标准值和设计值,对传统农居进行准确的砖砌体抗剪强度评估。本项研究主要为传统农居砖砌体结构的抗震性能评估、抗震加固以及抗震设计提供技术支持与科学依据。

高g值冲击下变截面填充壳缓冲性能优化方法

针对需要多个目标同时达到最优值,提出高g值冲击下泡沫铝填充变截面壳吸收能量最大化及测控电路承受加速度幅值最小化的多目标优化方法。以铝壳厚度和泡沫铝密度为设计变量,通过全因子试验设计选取试验点,同时利用LS-DYNA获取相应的冲击信息,引入响应面法构造近似目标函数,通过目标规划法获得最优解。结果表明,对于抗冲击性能的综合要求,多目标优化结果优于单目标优化结果,并在一定冲击载荷作用下对于选取更优的缓冲结构具有重要指导意义。

基于交通流模型的道路权重计算方法研究

提出了一种基于交通流模型的计算道路权重方法。实施定点道路截面雷达试验并采集交通流信息,标定生成交通流速度-密度模型。通过此模型,利用出租车行驶数据库中各条道路车速数据计算各道路车流密度,根据各道路长度和密度推算道路权重。

Bending tests and finite element analysis of lipped channels with complex edge stiffeners and web stiffeners

In order to study the bearing capacity and stability behavior of cold-formed steel flexural members with complicated sections,a total of 12 specimens divided into 6 groups were tested,including 3 groups of pure bending tests and non-pure bending tests each.There were three types of sections considered in this investigation,including channels with complex edge stiffeners(called B1-section),Σsection with complex edge stiffeners(called B2-section),and channels with complex edge stiffeners and V-type web stiffeners(called B3-section).Local buckling,distortional buckling and interaction buckling between them were observed in tests.The experimental results indicate that the bending strengths of B2-section specimens were the largest of these three types of specimens under the same conditions.It is found that the bending strength of B2-section specimens was increased by 6.47%for pure bending state and 8.12%for non-pure bending state,compared with that of B1-section specimens.Bending strength of B3-section specimens was almost the same with that of B1-section specimens under pure bending,but a little smaller than that of B1-section under non-pure bending state.It is also shown that B2-section specimens have better plastic deformation behavior than the other two sections.In addition,a non-linear finite element model was presented and verified against tests.The finite element analysis results agree well with experimental bending strength and failure modes.

织物增强混凝土增强砖砌体抗剪性能研究

通过对6组18个TRC增强砖砌体试件进行通缝截面抗剪试验,分析TRC中纤维编织网排布方式、层数、表面黏砂及基体中加入短切PVA纤维改性等因素对砖砌体抗剪性能的影响。试验结果表明：用TRC增强砖砌体可明显提高砌体抗剪强度;经向纤维与竖向灰缝夹角为90°的排布方式的试件平均抗剪强度提高了15.4%,斜向的排布方式的试件平均抗剪强度提高了21.7%;在一定范围内,增加纤维编织网的层数可以提高砖砌体抗剪强度;在纤维编织网表面黏砂可以提高砖砌体的延性;TRC基体中加入短切PVA纤维对提高砖砌体抗剪强度有影响,但影响程度较小。基于定滑轮原理,并考虑摩擦力,给出了TRC增强砖砌体的抗剪强度公式,计算结果与试验结果吻合较好。