摘要：Heat-assisted rotary draw bending(HRDB)is a promising technique for manufacturing difficult-to-form tubular components comprising high-strength titanium tubes(HSTTs)with small bending ***,as a multidie constrained and thermomechanical coupled process with many uncertainty factors,a high risk of several defects,such as cross-section distortion,over wall thinning,or even cracking,is *** the robust design optimization(RDO)of complex forming processes remains a nontrivial and challenging scientific ***,considering a high-strength Ti-3Al-2.5V titanium alloy tube as a case material,the five significant uncertainty factors in HRDB,i.e.,temperature distribution,tube geometrical characteristics,tube material parameters,tube/tool friction,and boost velocity had been ***,considering the preheating and HRDB of HSTT,a whole-process thermomechanical three-dimensional finite element model was established and validated for virtual ***,considering the maximum section distortion Q and maximum wall-thickness thinning t as the optimization objectives and the mean and variance of material and forming parameters,an RDO model was ***,the Pareto optimal solutions were obtained using the nondominated sorting genetic algorithm II,and a minimum distance selection method was employed to obtain the satisfactory *** show that the optimized solutions considering the uncertainty factors reduce the maximum section distortion rate of HSTT after bending by 38.1%and the maximum wallthickness thinning rate by 27.8%.

摘要：一关于文化的几点认识文化是一种社会现象,是人们长期创造形成的产物,同时又是一种历史现象,是社会历史的积淀物。文化是凝结在物质之中又游离于物质之外的,能够被传承的国家或民族的历史、地理、风土人情、传统习俗、生活方式、文学艺术、行为规范。

摘要：反应堆压力容器主螺栓紧固组件是保证其密封的重要部件,其螺纹副结构直接影响着反应堆压力容器的密封性能。结合国内外压水堆反应堆压力容器主螺栓螺纹副在设计、制造和安装方面的经验,对主螺栓螺纹副设计遵循的规范和标准要求进行了梳理和研究,并从主螺栓螺纹副承载和主螺栓安装两方面,分析了主螺栓螺纹副结构参数的影响。在上述研究成果的基础上,对主螺栓螺纹副结构进行了验证计算,为各堆型反应堆压力容器主螺栓螺纹副的结构设计提供技术参考。

摘要：提出了一种解决强干扰环境下输电线路工频参数测试难题的实用化新方法,描述了解决问题的关键技术,提出了一种测量进出线不在同一个变电站的线间互感(异地互感)的测试方法,并介绍了测试装置的硬件、软件设计及其实现。大量现场实测数据表明,基于同步电源的工频参数测试原理是可行的,所实现的测试装置较好地克服了强干扰电压对输电线路工频参数测试的影响,能很好地满足工程实际应用要求。

摘要：采光是智能遮阳系统的重要调控对象,而调控方法是智能遮阳设计的重要内容。研究梳理了以天然采光为导向的智能遮阳调控发展脉络,并总结了智能遮阳调控设计要点,提出结合当下机器学习技术的智能遮阳调控方法。通过脉络梳理,明晰了由物理实测采集闭环到数字模型预测开环的调控发展趋势,以及立足人工智能时代语境下趋向机器学习技术的交叉创新运用趋势。最后,研究基于系统性梳理,获取了智能遮阳采光调控设计要点,并结合机器学习相关技术,进一步提出机器学习辅助下的智能遮阳采光调控设计方法。为建筑智能遮阳调控设计和创新提供了技术性、科学性和可行性支持。

摘要：Plastic forming is one of enabling and fundamental technologies in advanced manufacturing chains. Design optimization is a critical way to improve the performance of the forming system, exploit the advantages of high productivity, high product quality, low production cost and short time to market and develop precise, accurate, green, and intelligent(smart) plastic forming technology. However, plastic forming is quite complicated, relating to multi-physics field coupling,multi-factor influence, multi-defect constraint, and triple nonlinear, etc., and the design optimization for plastic forming involves multi-objective, multi-parameter, multi-constraint, nonlinear,high-dimensionality, non-continuity, time-varying, and uncertainty, etc. Therefore, how to achieve accurate and efficient design optimization of products, equipment, tools/dies, and processing as well as materials characterization has always been the research frontier and focus in the field of engineering and manufacturing. In recent years, with the rapid development of computing science, data science and internet of things(Io T), the theories and technologies of design optimization have attracted more and more attention, and developed rapidly in forming process. Accordingly, this paper first introduced the framework of design optimization for plastic forming. Then, focusing on the key problems of design optimization, such as numerical model and optimization algorithm,this paper summarized the research progress on the development and application of the theories and technologies about design optimization in forming process, including deterministic and uncertain optimization. Moreover, the applicability of various modeling methods and optimization algorithms was elaborated in solving the design optimization problems of plastic forming. Finally, considering the development trends of forming technology, this paper discusses some challenges of design optimization that may need to be solved and faced in forming pr

摘要：铝合金小弯曲半径薄壁管数控绕弯成形是多模具约束、多因素影响的复杂成形过程,成形过程中极易出现起皱、破裂等成形缺陷,而模具材料和结构的合理设计对成形质量的影响至关重要。通过分析铝合金小弯曲半径薄壁管的结构特点,结合导管数控绕弯工艺过程,对模具材料选取、模具结构设计及成形仿真等关键技术问题进行了研究,最终确定了铝合金小弯曲半径薄壁管数控绕弯模具的材料、结构形式、尺寸参数,通过数控绕弯成形几何运动仿真、有限元数值模拟与工艺实验,实现了满足设计要求的铝合金小弯曲半径薄壁管数控绕弯成形,证明了小弯曲半径薄壁管数控绕弯模具的可行性,为工程化应用奠定了基础。

摘要：以国内某新型号压水反应堆压力容器主螺栓螺纹副为研究对象,对其进行了各安装工况下的旋拧模拟试验和拉伸标定试验。结果表明:新型主螺栓螺纹副的各安装参数推荐值可为主螺栓安装偏心度应不大于0.5 mm,主螺栓旋转速度应不大于30 rad/min,主螺栓剩余平衡配重应不大于40 kg,主螺栓允许的最大旋转力矩可不超过90 N·m;新型主螺栓剩余拉伸量计算值与拉伸标定值几乎一致,新型主螺栓绝对拉伸载荷与剩余拉伸载荷比值约为1.22,在工程经验范围值内,证明了新型主螺栓螺纹副结构设计的合理性,且新堆型主螺栓在所有工况下拉伸过程中的最大允许绝对拉伸量为4.13 mm。

摘要：以太阳能通风墙为研究对象,利用已建成的1∶1实体模型,针对不同构造的集热板、集热罩和热传输方式对太阳能通风墙热性能的影响进行了试验研究。试验结果表明,集热墙与地下蓄热式通风口同时开启的工况下,白天室内平均温度提高了7.6℃,夜间提高了1.8℃,且温度下降速率缓慢,有效地抑制了室温的波动;单框双玻塑钢集热罩腔体内温度白天的峰值为62.3℃,在20:00室外温度为6.1℃的情况下仍能达到16.5℃左右,比Ⅰ型高1.8℃,阻止了腔体热量损失的减少,提高了建筑的热稳定性;蓝膜集热板白天的集热效率比普通集热板高3%左右,夜间的保温性能更是比其高出了一倍。

摘要：随着社会的快速发展,科技不断进步。目前,以学习对象为主体的在线学习环境越来越普遍。面对互联网上海量的学习资源,传统的推荐系统不能为学习对象提供精准、有效的服务项目。基于此,将深度神经网络技术与资源推荐系统相结合,提出了基于深度神经网络的个性化学习资源推荐系统的设计思路,为学习者提供个性化的学习策略。