双腹板顶底角钢梁柱连接受力性能分析

建立双腹板顶底角钢梁柱连接节点的精细有限元模型,对模型进行了非线性有限元数值计算,分析了在单调荷载作用下双腹板顶底角钢梁柱连接节点的承载力、极限变形状态、破坏机理和变形状态.深入探讨了双腹板顶底角钢梁柱连接高强螺栓的预紧力,角钢与梁、柱之间的接触压力等节点组件之间的力学特性,获得试验难于测得的力学特性,为双腹板顶底角钢梁柱连接在工程中的应用提供理论依据.     

注装用改性B炸药渗油性的试验研究

通过中大口径榴弹战斗部注装改性B炸药后产生疵病的原因分析、实弹观察、注装过程物理特性及失效分析,参照TNT标准的渗油性试验方法,对原材料特性、制造工艺、长期储存所经历的任务剖面的综合分析及以相关试验为基础确定试验边界条件,提出改性B炸药的渗油性综合比较试验方案并进行检测,依此提出渗油性试验和工艺控制参数,为科学合理的评估注装弹药使用寿命周期提供试验依据.     

基于台架试验的动车组3人座椅整体分析

按有限元分析的标准,对动车组3人座椅的几何模型进行简化,确定材料属性及载荷工况,建立了有限元模型.根据企业要求和试验规范,利用有限元法对动车组3人座椅进行结构强度分析,并对结果进行讨论,提出了3人座椅的改进建议.     

新型风力/洋流涡轮气动及引射特性

为高效开发利用低品位风能和洋流能,采用涡扇发动机喷管引射技术,设计含有单级涡轮和波瓣引射器结构的低品位风力/洋流涡轮,给出一种波瓣引射器的参数化方法,并基于CFX软件RANS方程和k-ε湍流模型数值研究涡轮气动和引射特性.结果表明:含单级涡轮和波瓣引射器结构的低品位风力/洋流涡轮可将其转子四周流过的能量通过波瓣引射器引入涡轮后侧,通过流向涡和正交涡共同产生的抽吸作用,降低涡轮转子后侧被压,使有效做功速度增大约1.4倍,等效于提升了能量的品位.在2~6 m/s的风能和2~4 m/s的洋流能利用方面,含单级涡轮和波瓣引射器结构的风力/洋流涡轮功率曲线与来流速度成指数增长,流通能力增大32.70%~35.33%,在低速工况能量利用率可达66%~77%.     

双座阀在电厂叠加式改造中的应用实践

介绍在背压汽轮机叠加式改造中 ,采用新型的大口径双座阀替代后置机的实践。图 1参 4     

工程车辆座椅减振环节模型探讨

分析和讨论了几种不同结构的座椅减振模型,并用某工程车辆的基本数据进行座椅的结构参数优化计算。结果表明,这几种结构模型均取得了较好的减振效果,即良好的乘坐舒适性,为工程车辆驾驶座椅的设计提供了有益的参考。     

引进循环流化床锅炉15CrMo汽包管座与St45.8Ⅲ降水管厚壁异口径高压管道的焊接

引进芬兰的循环流化床锅炉，其汽包返包中国。降水管采用了德国碳素钢St45.8Ⅲ，与降水管相连的汽包管座采用了国产珠光体耐热钢15CrMo。该焊接头为高压、厚壁、异口径的焊接。文中介绍焊口所在的结构形式及工作条件，分析异种材料的焊接性能，并对其焊接及热处理工艺措施作了全面阐述。     

Evaluation of standing‐sitting support system with passive rotational seat mechanism in standing motion

Since a decrease in muscle mass of elderly people, the physical burden of them in standing‐sitting motion of a seat are increasing than young people. For this problem, several standing‐sitting support systems have been developed, and evaluations of these systems focusing on a reduction of physical load have been discussed. However, these evaluations are of support systems with an active actuators or of support systems when they use a handrail and a standing aid. Thus, an evaluation of a support system with only passive actuators has not been reported. In this paper, in standing motion with using a standing‐sitting support system with passive rotational seat mechanism which our group proposes, we objectively evaluate an effectiveness of the passive rotational seat mechanism by statistical analysis.     

Experimental research of drop‐on‐demand droplet jetting 3D printing with molten polymer

Three‐dimensional (3D) printing technology has become an effective method for parts manufacturing and got a certain application in many fields. Now, drop‐on‐demand droplet jetting 3D printing appears as a new method of manufacturing technology which has a proven research progress for metal, colloid, and liquid resin materials. However, there are hardly any researches of droplet jetting 3D printing with molten polymer. So, considering molten polymer as the jetting material with droplet jetting method is an explorative direction. In order to attain the molten polymer droplets and achieve droplet jetting 3D printing with molten polymer, the 3D printing technology of differential melt (3DPDM) is developed independently. According to 3DPDM, a complete set of drop‐on‐demand droplet jetting 3D printer have been developed. In this work, PP (6820) was chosen as the experimental material. Under the different print parameters such as the rotation speed of screw, nozzle diameter, mechanical impact frequency, heating temperature, the space between nozzle and platform, the form, and deposition of droplets were studied. Furthermore, the optimal print parameters were summarized. By printing models with the optimal print parameters, it turned out that the 3DPDM is able to achieve drop‐on‐demand droplet jetting 3D printing with molten polymer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45933.     

双层涤纶汽车座套面料的阻燃性能研究

选用不同比例的阻燃涤纶和普通涤纶长丝,设计织造了8种双层小提花织物,同时对织物进行了阻燃性能测试。结果表明:1#织物为最优织物,其采用接结双层组织,表里层为质量比1∶1的阻燃涤纶和普通涤纶,织物中使用的阻燃涤纶比例高,阻燃涤纶覆盖率系数大,织物的烫穿时间长,阻燃效果好。与纯阻燃涤纶织物相比,1#织物不仅达到了相同的阻燃效果,还减少了阻燃涤纶的使用量,节约了成本。设计织造的8种织物的阻燃性能均达到汽车用纺织品的阻燃要求,可以供企业在大生产中应用。