在压缩载荷下银杏果核破壳参数优化

利用LDS-W10A型微机控制的电子材料实验机对我国西南地区银杏果核进行了压缩实验,并以杏壳破裂力、破裂能耗、杏仁的破损率为目标参数,以施压部位、加载速率、含水率为因素进行了多目标的正交实验。同时,采用隶属度法的综合评分以及最小显著差值法(LSR法)优化出银杏果核脱壳的最佳工艺参数组合。通过对实验数据分析,得到相应的数学模型。实验表明:不同含水率的杏核在沿三个不同方向被压缩时,均出现明显的弹性变形,而且没有明显的生物屈服点;杏核施压方向、施压速率、含水率与综合评分指标均为显著相关(p0.05)。要使银杏果核脱壳质量最佳,其最优水平组合为杏核施压方向为Y轴、挤压速率为55mm/min、含水率23.72%。     

花生脱壳力学特性的实验研究

利用微机控制的电子拉压实验机对川西地区花生进行施压的力学实验。并以花生破损力为目标参数,以施压方向、施压速率、含水率为因素进行三因素三水平有重复观测值的正交试验。结果表明：花生壳厚沿不同部位均匀分布;花生在被压缩时,均会经过弹性变形、塑性变形和突然破裂3 个阶段;花生施压方向、施压速率、花生含水率对花生破损力都有极显著影响,并得到不同方向在弹性范围内的花生壳压缩与变形的回归方程,提出花生脱壳的最佳参数组合为花生施压力方向为顶面(x 向)、施压速率为30mm/min、含水率15.8%。     

刀豆脱壳力学特性的实验研究

利用万能试验机对刀豆的力学特性进行压缩实验.选择破壳力、破壳变形量和破壳能量为实验指标,以刀豆宽度、厚宽比、含水率、加载位置和试验机的施压速率为因素进行了混合水平正交实验和回归分析.结果表明,当沿荚果纵脊面平行压缩时,破壳效果理想,为脱壳的有效加压方向.含水率对破壳力和破壳能量的影响极显著,呈非线性正相关关系,降低含水率有利于提高脱壳率和减少设备能耗.加载位置、宽度和厚宽比对破壳变形量有显著影响,破壳变形量总体上随宽度和厚宽比的增大而减小.刀豆破壳力和破壳能量的综合最优水平组合:加载位置为中部,含水率为14.6％,施压速率为20rmm/rmin.     

葵花籽仁力学特性的有限元分析

为减少葵花籽仁在收获、储运过程中的机械损伤,并为相关机械的设计提供理论依据,根据测量得到的几何尺寸与试验得到的力学参数,建立了葵花籽仁的物理模型及有限元计算模型。通过有限元分析的方法,分析了葵花籽仁在不同载荷和作用方式下的破坏形式以及变形与应力的分布规律,并将有限元仿真结果与试验结果进行对比,验证了模型的可行性。结果表明:葵花籽仁的抗挤压能力具有各向异性,其沿X、Y、Z3个方向的弹性模量分别为E_X=64.01 MPa,E_Y=23.63 MPa,E_Z=101.8 MPa。相同压力下,葵花籽仁受到水平方向挤压时破碎的可能性最大,而竖直方向破碎的可能性最小;加载方向的不同使得籽粒的破坏形式不同,竖直方向加载时易产生局部裂纹破裂,而水平和垂直两向加载时籽粒会沿子叶夹缝开裂,其中垂直向加载时有失稳的可能。     

环境湿度向棉包内部传导特性研究

本研究探索了环境湿度向标准Ⅰ型棉包内部传导的基本规律。研究设计了三维立体式棉包内部湿度监测网络,分别沿棉包的长(Y轴)、宽(X轴)、高(Z轴)方向上设置了3层、2层和5层湿度监测传感器。棉包内外湿度相关性分析结果表明:当环境湿度较低时,棉包湿度以内部平衡为主,当环境湿度较高时,棉包内部湿度受环境湿度影响显著,且环境湿度沿不同方向传导时具有一定的差异。在Z轴方向上,棉包内外湿度的相关度均与深度成反比,相关系数0.412≤r≤0.761;在Y轴方向上,深度小于45 cm时,棉包内外湿度相关度与深度成反比,相关系数0.497≤r≤0.623,深度大于45 cm时,棉包内外湿度相关度与深度反比关系不再成立;在X轴方向上,棉包内外湿度相关度受深度影响小,相关系数0.553≤r≤0.561。本研究为进一步建立环境湿度向棉包内部传导的数学模型奠定了基础。     

板栗破壳力学特性的影响因素研究

用准静态压缩实验,对影响板栗破壳力的不同因素:加载方向、大小、加载速率、含水率以及板栗的几何形状进行了分析.结果表明,影响板栗破壳力的主要因素为板栗含水率、板栗大小以及加载方向;影响板栗破壳效果的主要因素有含水率、加载速率;在沿Y方向施加载荷时最省力;得出了板栗大小和破壳力之间的函数关系式及含水率与破壳力之间的函数关系式.     

影响板栗破壳力大小的因素

用准静态压缩试验,对影响板栗破壳力的不同因素——加载方向、板栗大小、加载速率、板栗含水率以及板栗的几何形状进行了分析。结果表明,影响板栗破壳力的主要因素为板栗含水率、板栗大小以及加载方向;在沿Y方向施加载荷时最省力;由单因素试验得出了板栗大小和破壳力之间、板栗含水率与破壳力之间的函数关系式;由多因素试验得出了板栗大小、含水率以及加载速率和破壳力之间的函数关系式。     

丝网印刷专利产品集锦

<正>一种印刷网版喷印设备专利申请号:CN201420224543.7公开号:CN203854304U申请日:2014.05.04公开日:2014.10.01申请人:王琦、罗炳军本实用新型公开一种印刷网版喷印设备,打印头安装在X轴移动机构上,X轴移动机构带动打印头沿X轴方向移动;X轴移动机构安装在Y轴移动机构上,Y轴移动机构带动X轴移动机构沿Y轴方向移动;网框位于打印头的下方,网框通过支架安装在打印平台上;工控机分别于X轴移动机构、Y轴移动机构和打印头连接,并分别控制X轴移动机构、Y轴移动机构和打印头动作。与现有技术相比,本实用     

文冠果种子力学性能分析

通过万能材料试验机进行文冠果种子静态压缩破壳试验,并进行了三因素三水平正交试验,以含水率、加载速度、加载方向为因素,以初次破壳力、位移量、破壳应变能为指标,分析文冠果种子力学特性。结果表明:初次破壳力随着含水率的减少基本呈现上升趋势,位移量、破壳应变能随含水率的减少大致呈现下降趋势,在加载速度为5、10、15 mm/min时,x轴上的初次破壳力、位移量和破壳应变能基本均小于其他两个方向的;文冠果种子综合破壳效果的影响因素由大到小依次为含水率、加载方向、加载速度;最佳破壳条件为含水率37.14%、加载方向x轴、加载速度15 mm/min,在此条件下,初次破壳力为104.445 N。     

温185核桃压缩力学特性研究

为了进一步改进核桃破壳装备的设计与制造,利用万能材料试验机研究核桃压缩破裂的力学过程,分析含水率、加载速度对核桃壳破裂力学参数的影响。沿3个加载方向压缩核桃和空核桃壳,对比分析核桃壳体的破裂过程。在4种不同加载速度(100,200,300,400mm/min)下,对4种含水率(4%,6%,8%,10%)的空核桃壳进行压缩试验,测定核桃壳的破裂力、破裂功、破裂功率和理论弹性模量,并对各力学参数进行显著性分析。结果表明,核桃壳体破裂属韧脆性断裂,空壳核桃壳体在线性区间内的破裂力学参数能较好地反映核桃壳体的压缩力学特性。随含水率和加载速度的变化,核桃壳体的各力学参数呈一定规律变化,且含水率、加载速度对核桃壳线性区间的破裂力、破裂功、理论弹性模量的影响显著,对核桃壳线性区间的破裂功率的影响不显著。     

油莎豆的剪切力学特性

为选择适宜的油莎豆破碎设备,探究了脱皮前后油莎豆剪切力学特性变化。以油莎豆为试验原料,利用物性分析仪,在初步考察脱皮对油莎豆剪切特性影响基础上,分别探讨了水分含量、加载速率、加载方位和粒径等级对未脱皮和脱皮油莎豆破坏力、硬度和破坏能的影响。结果表明：脱皮对油莎豆的剪切特性存在影响;水分含量、加载速率、加载方位和粒径等级均对未脱皮和脱皮油莎豆的破坏力、硬度和破坏能具有显著影响。未脱皮和脱皮油莎豆的破坏力、硬度和破坏能随油莎豆水分含量增大以及粒径的减小而降低,随加载速率增加呈先增大后降低的趋势,并在加载速率为0.3 mm/s时获得较大值。在抗剪切能力上脱皮油莎豆X轴最大,Z轴次之,Y轴最小,未脱皮油莎豆Z轴最大,X轴次之,Y轴最小。此外,在相同的剪切条件下,脱皮油莎豆的破坏力、硬度和破坏能均远低于未脱皮油莎豆的。研究结果可为油莎豆加工机械改进和工艺条件制订提供必要的理论依据。     

Effects of moisture content and compression axis on mechanical properties of Shea kernel

Some mechanical properties of Shea kernel were investigated in this study. The kernels were divided into two categories sizes namely: small size kernel (SSK) and large size kernel (LSK) and the properties investigated were: rupture force, deformation at rupture and energy consumed at rupture. The tests were carried out at a deformation rate of 50 mm/min and four moisture content levels of 25.9%, 11.60%, 6.88%, 4.98% (db) for SSK and 11.19%, 6.21%, 5.78% and 2.77% (db) for LSK. The variations in these properties were observed considering the effects of moisture content and compression axes on them as the kernels were air-dried. Sample kernels were compressed along the orthogonal axes corresponding to major axes (length), intermediate axes (width) and minor axes (thickness) of Shea kernel. Some physical characteristics of Shea kernel such as dimensions, geometric mean diameter and mass were also evaluated. Results showed that generally, rupture force, deformation and energy at rupture decreased as moisture content decreased. The regression models that best fitted the relationships were polynomial functions of the second order. The highest and lowest forces for Shea kernel to rupture were those through the minor axis (thickness) and major axis (length) respectively. These properties are often required for the design of transportation, storage and grading/sorting machines and other post harvest machines for Shea kernel.     

Mechanical Behavior of Lentil Seeds in Relation to their Physicochemical and Microstructural Characteristics

The mechanical characteristics (rupture force, maximal deformation, and rupture energy) of red and green lentils under compression loading were determined as a function of moisture content ranging from 9.5 to 21.1% (w.b.). Scanning electron microscopy, laser diffraction particle size analysis, and instrumental texture evaluation were successfully applied to relate the microstructure and texture of different lentil seed varieties. Results demonstrated that all of the mechanical parameters of the green lentils, which have smaller starch granules, were significantly (p < 0.05) higher than those of the red lentils. At a loading rate of 4 mm min^?1, the force required for initiating seed rupture decreased with an increase in moisture content, for vertical and horizontal orientations (p < 0.05). The scanning electron microscopy observations also revealed that seeds were more flexible in a horizontal orientation.     

Mechanical behavior of pistachio nut and its kernel under compression loading

Some mechanical properties of five varieties of Iranian pistachio nut and its kernel (namely; Akbari, Badami, Kalle-Ghuchi, Momtaz and O’hadi) were determined. These properties include rupture force, deformation and rupture energy. Samples at various moisture contents were compressed along the X-, Y- and Z-axes. The X-axis was considered the loading axis through the length dimension, while the Y-axis was the transverse axis containing the minor dimension (width) at right angles to the X-axis, and Z-axis was assumed the transverse axis containing the minimum dimension (thickness). The results showed that rupture force, deformation and rupture energy values decrease with increasing moisture content. The maximum rupture force, deformation and rupture energy values at all moisture levels as well as for all varieties were obtained for pistachio nut loaded along the X-axis. Compression along the Y-axis required less compressive force among the other two compression axes to extract the kernels.     

Geometric and Mechanical Properties of Mung Bean (Vigna Radiata L.) Grain: Effect of Moisture

In this research, selected geometric and mechanical properties of mung bean grain were evaluated as a function of moisture content. Five levels of moisture content ranging from 7.28 to 17.77% d.b. (dry basis) were used. The average length, width, thickness, arithmetic and geometric mean diameters, sphericity, thousand grain mass and angle of repose ranged from 5.145 to 6.199 mm, 3.760 to 4.474 mm, 3.537 to 4.223 mm, 4.147 to 4.965 mm, 4.090 to 4.893 mm, 0.795 to 0.789, 52.3 to 64.6 g, and 25.87 to 29.38° as the moisture content increased from 7.28 to 17.77% d.b., respectively. The bulk density was found to be decreased from 821.3 to 745.2 kg/m³, whereas the grain volume, true density, porosity, terminal velocity, and projected area were found to be increased from 27.88 to 47.33 mm³, 1230.0 to 1456.7 kg/m³, 30.43 to 46.57%, 4.86 to 5.29 m/s, and 17.48 to 19.26 mm², respectively. There is a 43% increase in surface area from grain moisture content of 7.28 to 17.77% d.b. The static coefficient of friction on various surfaces increased linearly with the increase in moisture content. The rubber as a surface for sliding offered the maximum friction followed by galvanised iron, medium density fibreboard, stainless steel, aluminium and glass sheet. As moisture content increased from 7.28 to 17.77%, the rupture forces values ranged from 67.39 to 39.44 N; 63.86 to 42.18 N, and 53.96 to 41.79 N for thickness (Z axis), length (Y-axis) and width (X-axis), respectively.     

Mechanical behaviour of hazelnuts used for table consumption under compression loading

Nuts of four hazelnut varieties and five new selections used for table consumption were compressed at the moisture content of 6% wet basis to measure shell resistance to breakage. Rupture force, rupture energy and nut specific deformation were measured under three compression loading positions. Physical parameters of nuts were also evaluated to relate them to the data obtained by compression test measurements. Rupture force and nut specific deformation are the most discriminant parameters that can be used to describe the behaviour under compression, while rupture energy values show fewer differences among the considered varieties. The values of force required to break nut shell ranged from 322.2 to 769.3 N. The lowest values of force were generally obtained along the y‐axis, the transverse axis containing the major dimension at right angles to the longitudinal axis. Nut specific deformation ranged from 3.35 to 11.76%. Correlations between physical and texture parameters showed that values of force, energy and deformation were dependent on different parameters that varied in the three considered axis. The most used varieties, Ennis and Barcelona, showed high mean values of force rupture to break shell and low deformability, while Tonda Giffoni and Tonda Bianca were easy to break. Among the new selections, L35 and B6, with mean values of force rupture less than 428 N and values of nut specific deformation higher than 8%, were suitable for table consumption. Copyright © 2006 Society of Chemical Industry     

Microwave Inactivation of Myrosinase in Canola Seeds: A Pilot Plant Study

Optimum conditions for microwave inactivation of myrosinase in Canola seeds were investigated with a response surface design. The linear effect of variables (i.e. moisture content, microwave power and exposure time), the second order of exposure time and interaction between exposure time and microwave power were significant for the enzyme inactivation response (P<0.05). A significant (1%) regression equation which could predict the extent of enzyme inactivation at practical levels of moisture, and microwave power was tested. The coupled microwave energy required for complete enzyme inactivation was moisture dependent. The energy required was independent of seed variety. Microwave treatment caused significant increases in the yellow color and sulfur content of the seed oils.     

Deformation and Dehulling of Sponge Gourd (Luffa aegyptiaca) Seeds

This work presents the compressive strength properties of sponge gourd (Luffa aegyptica) seeds to facilitate the design or adaptation of an appropriate dehuller. The sizes and shape indices of the seed and kernel, and the clearance of the kernel from the seed coat were determined. The seed samples were subjected to uni-axial quasi-static compression tests at 1.0 mm min^?1 along the minor and the major axes. The fracture resistance, stiffness modulus, modulus of elasticity, toughness, and maximum elastic deformation of the seed were obtained from the force-deformation curve. The geometric mean diameters varied from 4.0 to 4.5 mm for the seed and 1.6 to 3.9 mm for the embedded kernel; while their corresponding sphericities were 0.64 and 0.62, respectively. The compressive strength of the seed varied with loading orientation. The seed exhibited larger deformation but lower stiffness along the major axis than the minor axis. The force required for rupturing the hull were 95 N along the major axis and 81 N along the minor axis; while the corresponding energy required were 95 and 40 mJ.     

新丰核桃的多因素压缩试验

通过对新丰核桃进行挤压试验,研究含水率、加载速度及加载方向对核桃压缩特性的影响,并对核桃挤压破壳建立有限元模型分析,运用ANSYS对核桃在不同加载方向下的力学特性进行仿真。结果表明,核桃在厚度方向进行挤压破壳时所需的破壳力最大,此时的核桃壳裂纹扩散面积也最大,核桃壳破裂发生的形变最小,易于取出较完整的仁。挤压式和击打式两种破壳试验表明,多次多范围的冲击式加载能使核桃壳裂纹扩散率更大更均匀,得到的整仁率越高,能达到更好的破壳取仁效果。     

The Effects of Moisture Content, Compression Speeds, and Axes on Mechanical Properties of Walnut Cultivars

In this study, the mechanical properties of walnut (Juglans regia L.) cultivars were investigated as a function of moisture content. The experiments were carried out at three moisture contents, compression speeds (0.5, 1, and 1.5 mm/s), and compression axes (X-, Y-, and Z-axes). The highest rupture force and rupture power in all moisture contents were obtained for walnut cultivars loaded along the Y-axis. Rupture force, rupture energy, and rupture power of walnuts decreased in magnitude with an increase of moisture content, while rupture force, specific deformation, rupture energy, and rupture power increased with an increase of compression speeds. The highest rupture force was obtained with load along the Y-axis as 410.4 N and 394.3 N and also the highest rupture force was recorded at 1.5 mm/s compression speed as 260.7 N and 377.1 N for Yalova-1 and Yalova-3 cultivars, respectively. A linear force decrease was observed from 320.5 N to 196.4 N and from 492.7 N to 247.1 N with increasing moisture content from 11.46% to 23.16% and from 11.25% to 19.47% for Yalova-1 and Yalova-3, respectively. The highest rupture force, specific deformation, rupture energy, and rupture power were obtained at 1.5 mm/s compression speed, while the lowest rupture force was obtained at 0.5 mm/s compression speed for walnut cultivars. The lower rupture force and rupture power were obtained with load along Z-axis for Yalova-1 and Yalova-3 walnut cultivars. The results revealed that the higher compression speed and Z-axis could be recommended for cracking of shelled walnuts.