Design Method of Curved-bar Refining Plates for Disc Refiner

Straight-and curved-bar refining plates are two important types of plates commonly used in disc refiners in the papermaking industry.Theoretically,the curved-bar refining plate has a relatively uniform bar interaction angle,which indicates uniform refining effects.The bar angle of the curved bar was proposed and two typical curved-bar plates,the three-stage radial curved-bar plate and isometric curved-bar plate,were designed in this paper.The arc equations of the curved-bar center line and curved-bar edges were established and finally,the specific edge load(SEL)of the curved-bar plate was derived.The determination of bar parameters was discussed,which provides a theoretical basis for the design of curved-bar plates.

Design and Kinematics Analysis of a Parallel Mechanism to be Utilized as a Luggage Door by an Analogy to a Four – Bar Mechanism

In this study, a luggage door mechanism to be used in commercial vehicles such as midibuses and buses is designed and analyzed. The mechanism is designed as a parallel hinged system. Velocities, rotational veloci- ties and rotational accelerations of selected points on the design are calculated. Furthermore, the experiment- tal model of the design is established and it is seen that the data taken from the model are compatible with the calculated results. The aim of this study is to design a mechanism with the minimal workspace so that the door can be utilized in narrow areas and the ergonomics of the luggage door is improved. Considering both commercial and passenger vehicle sales, vehicle interior and exterior trim features have an exceptionally important role in automotive industry, in addition to vehicle performance characteristics. In today’s compete- tive environment, parts used in a vehicle’s internal and external trim have to meet user demands in terms of ergonomics as well as aesthetics. Due to its similarity to a four-bar mechanism, kinematics analysis of the design was carried out based on a four-bar mechanism, which is used extensively in industry.

Computer-aided Pattern Design of Multi-bar Warp Knitted Fabrics

To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the computer-aided pattern design of multi-barwarp knitted fabrics.In terms of the special propertiesof the computer-aided pattern design of multi-barwarp knitted fabrics,the Object Oriented Program(OOP)programming-Object Windows class Library(OWL)programming is selected.According to thecharacters of the OWL programming,various functionsare defined.Pattern design and technical parameters canbe output,which offers a great convenience for the fac-tory.

Structure optimal design research on backfill hydraulic support

Backfill hydraulic support is the key equipment in achieving coal mining and solid backfilling simultaneously in solid backfill mining technology.Based on the summary and analysis of main types,basic structural properties and filed application of backfill hydraulic support,this work has firstly proposed the basic principle of backfill hydraulic support optimization design and provided the method of optimal design of key structural components,like four-bar linkage,rear canopy and tamping structure;the method is further elaborated as changing hinging position of upper bar to optimize four-bar linkage,by lengthening or shortening the rear canopy to optimize length ratio of canopy;and by changing length and hinging position of tamping structure as well as suspension height of backfill scrape conveyor to realize optimization of tamping structure.On this basis,the process of optimal design of backfill hydraulic support is built.The optimal design case of ZC5200/14.5/30 six columns-four bar linkage used in 7203 W workface of Zhaizhen Coal Mine shows that the backfill properties like horizontal roof gap,vertical horizontal gap,tamping angle and tamping head gap are improved obviously through optimizing four-bar linkage,canopy length and tamping structure according to the optimal design method proposed in this work.

焊接锚垫板锚固区拉压杆模型及配筋设计

针对焊接锚垫板齿板锚固区配筋,提出了一种锚固区新型拉压杆模型。首先对齿板锚固区6种典型效应、主应力迹线以及力流平衡关系进行分析并建立新型拉压杆模型,其次通过美国国家公路与运输官员协会(American Association of State Highway and Transportation Officials,AASHTO)Load-and-resistance Factor Design Bridge Design Specifications、Building Code Requirements for Structural Concrete and Commentary(ACI 318-19)、《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG 3362—2018)和欧洲设计建议Practical Design of Structural Concrete进行拉压杆模型参数定量化设计,根据拉压杆几何关系推导出焊接锚垫板齿板锚固区劈裂力计算式,利用有限元分析,拟合出焊接锚垫板下齿板锚固区劈裂力合力重心计算式。最后通过算例分析,按本文建议的拉压杆方法进行焊接锚垫板齿板锚固区结构配筋设计,能较好地控制锚下典型效应问题,相比《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG 3362—2018)给出的设计方法,拉压杆模型法能较好地反映结构传力机制且具备可行性和可应用性,可为焊接锚垫板齿板锚固区配筋设计提供参考。

A METHOD OF ADJUSTING BAR-LENGTH OF STATICALLY INDETERMINATE TRUSS FOR INCREASING ITS LOAD CAPACITY

Based on the character of the internal force distribution of the statically indeterminate truss, the elements stresses were changed by adjusting the length of bars to increase load capacity of structure. The efficiency of the method is illustrated by several examples.

镗杆切削力感知单元结构设计与优化

为满足测量镗杆切削力的需求,采用ANSYSWorkbench有限元分析软件对镗杆等效应力与等效应变分析,确定感知单元安装位置。提出两种镗杆感知单元结构,运用响应曲面优化法确定感知单元最佳优化方案,通过计算、分析相关参数,来确定最佳的优化方案,并与优化前的感知单元结构方案进行比较。结果表明:当未超过应变式微力传感器最大等效应变时,均布式感知单元结构中镗杆最大测量值为329N;以附加支撑感知单元最大测量值为1000N为设计目标,获得5种最优结构参数,在实际设计制造中,可根据实际情况从中进行选择。

人体下肢康复装置的结构设计及运动学分析

介绍了一种基于平面五杆机构的人体下肢康复装置,旨在满足术后卧床的卒中患者的早、中、后期的下肢康复训练需求。该装置具有简单可靠的特点,可以在床尾侧放置或随患者行走移动。装置主要由下部移动平台、手动升降组件、上部动力传动机构及左、右训练机构组成,并在踝、膝关节通用的关节支架上附有传感器,患者的运动信息可以被实时采集和反馈。运动学分析及Adams软件仿真结果表明,调整该装置双曲柄的初始相位,可以改变关节点的运动轨迹,得到不同运动模式下人体下肢关节运动的范围,达到卧式训练及行走训练的目的,从而满足患者不同康复阶段的训练需求。

Optimization of Steel Bar Manufacturing Process Using Six Sigma

Optimization of a manufacturing process results in higher productivity and reduced wastes. Production parameters of a local steel bar manufacturing industry of Pakistan is optimized by using six Sigma-Define, measure, analyze, improve, and controlmethodology. Production data is collected and analyzed. After analysis, experimental design result is used to identify significant factors affecting process performance. The significant factors are controlled to optimized level using two-level factorial design method. A regression model is developed that helps in the estimation of response under multi variable input values. Model is tested, verified, and validated by using industrial data collected at a local steel bar manufacturing industry of Peshawar（Khyber Pakhtunkhwa, Pakistan）. The sigma level of the manufacturing process is improved to 4.01 from 3.58. The novelty of the research is the identification of the significant factors along with the optimum levels that affects the process yield, and the methodology to optimize the steel bar manufacturing process.

Performance Analysis of a Six-bar Linkage Pumping Unit Based on a Small Fluctuations Load Shape

Crank shaft net torque of pumping units is a volatile alternating load, while output torque of a general motor is basically constant. Thus, load characteristics of pumping units and motors are not able to ＂harmoniously＂ match each other; this resulted in a higher output of the motor, lower efficiency, and higher energy consumption of the pumping units. A new six-bar linkage pumping unit is presented according to moment-changing theory. It allows to adjust automatically following the changes of polished rod load, and achieves small crank shaft curve fluctuation. The new pumping unit improves motor efficiency, reduces motor output power, and saves energy. According to the design scheme, kinematics and kinetics models of the new six-bar linkages pumping unit are built up. An optimum design on the main peoCormance parameters and functional analysis were peoCormed.

红线女大剧院小红豆书吧公共空间设计

通过红线女大剧院小红豆书吧公共空间设计实践案例,阐述以传统粤剧服饰之美为核心要素,将粤剧服饰数字展与粤剧时尚视觉的多元化形式结合,塑造粤剧文化艺术特色休闲娱乐公共书吧,为非遗的创新性传承提供现实的思路。

基于响应面法的牵引杆轻量化设计

针对牵引杆的轻量化设计问题,提出了采用响应面法与有限元分析相结合的轻量化设计方法。利用多目标优化算法求解响应面法得到的拟合数学模型,然后利用有限元分析方法进行检验和优化。结果表明,轻量化设计后的牵引杆试验机质量为151.77kg,最大应力值为336.17MPa,满足预期目标,证明该轻量化设计方法的有效性。

图像学视域下18世纪法国女性服饰中的条形纹样研究

18世纪的法国是欧洲时尚的中心,在政治上是封建君主制盛极而衰的转向时期,审美趣味也经历了从巴洛克、洛可可转向新古典主义的变化。服饰作为阶级身份的象征,伴随着社会政治和文化的变化而变化。文章从18世纪法国丝绸服饰面料花型样本、丝绸女装实物和女性人物肖像画3种史料维度着手,通过图像学研究视角对这一时期女性服饰呈现出的条形纹样的设计特点进行研究,探讨社会阶级流动、审美趣味转型和生产技术革新对这种设计风尚的影响。

刨磨质量和工艺对竹条制轴压构件力学性能影响

【目的】研究刨磨质量和手工工艺对1 mm×6 mm竹条制作的轴心受压短杆和长杆基本力学性能的影响。【方法】采用不同初始质量的竹条,通过刨磨掉不同质量制作了112个截面尺寸为6 mm×6 mm的箱型空心受压杆件;测试了空心杆件的质量和极限承载力,并计算了荷质比;最后,探讨了3种不同刨磨工艺对杆件受力性能的影响。【结果】打磨后竹条制的空心短杆质量降低到原来的1/2,但承载力可达350~550 N,荷质比在560 N·g^(-1)以上。【结论】模型制作中竹材选材时,对长杆选择初始质量小的竹条刨磨,对短杆选择初始质量大的竹条刨磨;研究成果可为全国大学生结构设计竞赛杆件选材与制作提供参考。

西藏某钢框架住宅结构设计

因钢框架结构相对混凝土结构具有自重轻、强度高、抗震性能好、施工周期短和节能环保等优点,在西藏某政府周转房设计中采用装配式钢框架结构形式,对钢框架结构在高层住宅中的应用进行技术探讨。首先,根据建筑布置及初步结构计算,确定钢框柱、梁、板的布置及截面尺寸;其次,用PKPM计算结构的各项性能指标;最后,进行节点和楼梯及防火设计。结果表明:结构模型的各项指标均满足现行规范要求,该设计方案是可行的,可供相关工程参考。

可变二维码印制要点研究

为了提升可变二维码的首读率,提高数据共享效率,更好地发挥可变二维码数据共享中的作用,特开展可变二维码印制质量研究。本文采用试验分析法,研究可变二维码生成软件参数设置、承印基材表面处理技术要求、喷印设备控制对其质量等级的影响。确定了可变二维码印制前承印材料预处理应达到的要求,承印材料光学特性参数不透明度、符号反差、最小边缘反差预测值。通过优化可变二维码设计、严格承印材料表面处理和控制喷码过程,可有效提升可变二维码印制质量。

压力棒牵伸区中的纤维数量分布模型

牵伸区中纤维的运动状态受与其接触纤维状态的影响,为研究牵伸区中纤维的运动状态,对上托式压力棒牵伸区中各类纤维的数量分布进行了研究。分析了牵伸区中各类纤维的理论分布,测量了牵伸区中的各类纤维数量分布,简化了纤维数量分布曲线。再通过均匀设计,测试了不同牵伸参数下的变细曲线,建立了变细曲线与牵伸参数之间的回归方程,最终得到了牵伸区中的纤维数量分布模型。结果表明:牵伸区中各类纤维的数量分布受牵伸倍数、罗拉握持距、纤维长度、压力棒位置等牵伸参数的显著影响,纤维的数量分布可基于总纤维、前纤维和后纤维的数量分布得到。回归方程的平均拟合误差在7%以内,所建立的纤维数量分布模型适用于涤纶和粘胶纤维。

大学生结构设计竞赛中空间杆系结构力学特性分析

针对历年大学生结构设计竞赛中空间杆系结构的赛题,以复压竹皮和竹杆为原材料设计空间杆系结构并进行其结构形式分析。利用有限元软件MIDAS Gen建模和计算,对系列空间杆系结构在多种荷载工况下的应力和位移进行数值模拟仿真,分析其承载能力和变形特征,总结出空间杆系结构在荷载组合工况下的强度、变形等力学特性以及结构优化的有效措施。

电池抗高g值冲击性能的研究

针对在高g值冲击下,弹载存储测试装置的电池模块发生爆炸而导致测试失败的情况,选取测试装置常用的几种电池,利用Hopkinson杆对其在不同方向(沿平行和垂直的冲击方向)和石蜡灌封的状态下进行了抗高g值冲击性能试验。研究结果表明,经过冗余设计的电池有很高的抗冲击性。在约30万g的加速度冲击下,所试验的电池均没有发生爆炸。在目前弹体侵彻各种目标的加速度幅值范围内,所采用电池的可靠性可以保证。

基于BIM的铁路预制箱梁钢筋设计加工一体化研究

针对铁路预制箱梁钢筋工程存在的设计水平不高、生产方式落后等问题,开展基于BIM的铁路预制箱梁钢筋设计加工一体化研究。建立铁路预制箱梁钢筋一体化设计理论,利用Tekla软件完成梁体BIM设计及钢筋精细化设计,主要解决钢筋与预应力管道、锚具、泄水孔干扰等问题;运用大数据、云平台、物联网等技术,开发数据转化软件、生产管理系统、车间控制系统,并与设备厂商联合研发钢筋自动加工成套专用装备。在津潍铁路箱梁钢筋工程进行现场应用,结果表明,该研究能够提升铁路预制箱梁钢筋工程的自动化水平,可为其他类似工程提供参考。