共查询到20条相似文献,搜索用时 356 毫秒
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常用缓冲材料动态压缩特性研究 总被引:11,自引:8,他引:3
通过对三种常用缓冲材料进行动态压缩试验,研究缓冲材料的动态压缩特性,绘制出动态压缩特性曲线,找出其规律,及材料的密度,厚度、跌落高度对动态压缩特性曲线的影响,指出动态对缓冲包装设计的影响。 相似文献
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缓冲材料冲击试验机的数据采集和处理系统 总被引:7,自引:0,他引:7
缓冲材料的缓冲特性是缓冲防振包装设计的重要依据。材料的缓冲特性可用最大加速度—静应力曲线或缓冲系数—最大应力曲线表示。材料缓冲特性的试验方法有动态压缩试验法和静态压缩试验法,与静态压缩试验法相比,动态压缩试验法更接近包装件跌落的实际状况,所以测试结果... 相似文献
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生物质燃料压缩成型技术研究进展 总被引:1,自引:0,他引:1
《化工新型材料》2016,(9)
介绍生物质燃料压缩成型技术的基本原理、生产工艺及研究现状,重点讨论影响生物质燃料压缩成型的因素、生物质燃料的物理特性和燃烧特性,指出生物质燃料压缩成型技术在实际生产中存在的问题及未来发展方向。 相似文献
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沈海军 《材料科学与工程学报》2009,(1)
采用分子动力学方法,模拟了石墨层垛堆纳米纤维(GLSNF)与110°、62°锥垛堆碳纳米纤维(CSCNF)的轴向压缩过程,探讨了加载速率、温度等对三种碳纳米纤维力学特性的影响以及它们之间压缩力学特性的差异。研究表明,温度越低、加载速率越高的情况下,各碳纤维的承压能力与承受变形能力越强;相同加载速率和温度下,62°CSCNF的轴向压缩力学特性最好,GLSNF的压缩力学特性最差。 相似文献
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目的解决库尔勒香梨在包装、运输过程中因静压产生的香梨损伤问题。方法在不同压缩速率、不同摆放位置、不同缓冲压头条件下,利用万能试验压缩机测量分析香梨机械特性参数变化规律。结果各压缩特性参数的分布规律大致相同,生物屈服极限、破坏极限、变形能、破坏能均随着压缩速率的增大逐渐增大,屈服极限、破坏极限在随压缩速率增大而增加的过程中有极值存在。香梨纵向部位压缩特性参数均大于横向部位压缩特性参数。在相同摆放位置下,泡沫缓冲压头的压缩特性参数最大,钢板压头下的特性参数最小。当速率为30 mm/min时,在泡沫缓冲压头下,香梨横向摆放时的生物屈服极限为105.98 N,变形能为242 N·mm,破坏极限为155.25 N,破坏能为582N·mm。香梨纵向摆放时的生物屈服极限为135.91 N,变形能为521 N·mm,破坏极限为177.07 N,破坏能为942 N·mm。结论不同缓冲压头下的压缩特性参数曲线分布规律大致相同,屈服极限和破坏极限在随压缩速率增大而增加的过程中有极值存在。香梨纵向摆放受到外界的机械损伤小于横向摆放所受的机械损伤,在香梨包装、贮藏、运输过程中应考虑摆放位置,尽可能让香梨纵向受力。当使用泡沫材质进行包装时,香梨机械损伤最小,在香梨包装时应考虑选用泡沫包装材质。 相似文献
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植物材料粉粒体经过压缩成型,可以使其形状尺寸整体划一,制成成型燃料、成型饲料和各种成型产品。其压缩成型过程的压缩变形、压力分布与成型机理问题是模具形体设计和产品开发的基础。本文根据作者多年的实验数据,给出了植物纤维粉粒体在压缩成型过程的压力-变形关系、即压缩特性,压力在圆筒型体中的传播特性和成型机理,为植物材料转化利用提供理论基础。 相似文献
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研究了真空辅助树脂注射(VARI)工艺中含定型剂织物定型参数对织物压缩特性、渗透特性及其复合材料力学性能的影响,确定织物最优的定型参数。采用DSC和IR分别对织物表面定型剂的熔融特性和组成进行了分析,测试了不同定型温度下的压缩、渗透特性及复合材料力学性能。结果表明:此定型剂为含有环氧基团的低熔点聚合物;低于100℃时,随着定型温度的升高,织物的压缩厚度和渗透率均下降;100~140℃时,随着定型温度的升高,织物的压缩厚度基本无变化,渗透率有所提高,定型温度对力学性能基本无影响。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill. 相似文献
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Dimiter Hadjistamov 《材料科学与工程:中英文B版...》2019,(2):56-65
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ... 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献
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《中国标准化(英文版)》2014,(5)
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively. 相似文献