甘蔗—土壤系统仿真模型的研究
摘要
目前国内外对甘蔗收获机械切割系统的研究主要集中在甘蔗切割破坏、切割能量、破头率影响因素试验研究、切割器优化设计和甘蔗切割运动学仿真等方面,关于甘蔗—土壤系统仿真模型的研究未见报道,但甘蔗—土壤系统仿真模型的建立对开展甘蔗切割动力学仿真研究及指导室内甘蔗切割模拟试验有重要意义。
研究选取台糖22号甘蔗及其种植的壤土(水稻土)作为研究对象,采用物理试验方法,测得了甘蔗密度,蔗芯、蔗皮的弹性模量和甘蔗茎秆的屈服应力;运用振动衰减法,通过田间振动试验,获得甘蔗和甘蔗—土壤系统的振动加速度曲线,并进行相关分析;采用有限元分析软件ANSYS/LS-DYNA建立甘蔗和甘蔗—土壤系统仿真模型,运用反求技术和正交试验法,以参数初始值为基础,不断修改系统的物理特性参数,进行仿真试验,获取甘蔗—土壤系统仿真振动加速度曲线,并和物理实验测试甘蔗振动加速度曲线对比,获得和实际甘蔗物理特性参数相接近的甘蔗—土壤系统仿真模型的系统参数;根据仿真模型提供的系统参数,选择海绵橡胶板和海绵橡胶带来分别模拟硬土壤和软土壤对甘蔗的抱紧作用,设计甘蔗抱紧装置并进行物理试验验证。
结果表明:蔗皮的密度平均值为1067kg/m~3,弹性模量平均为194.07MPa,蔗芯平均为41.75Mpa,甘蔗茎秆的破坏应力平均为15.34Mpa;甘蔗和土壤材料均为塑性随动模型,其中甘蔗参数为密度1067kg/m~3,弹性模量1.00E8Pa,泊松比0.4,屈服应力1.50E7Pa,切线模量1.80E5Pa,应变速率(c)100,应变速率(p)10,失效应变率0.01,阻尼2;软土对应参数为1910kg/m~3,1.00E6 Pa,0.4,8.00E5 Pa,1.00E5 Pa,41,6,0.8,2.2;硬土对应参数为1850 kg/m~3,1.50E6 Pa,0.35,8.50E4 Pa,1.20E5 Pa,38.5,0.7,2;甘蔗以及甘蔗.土壤系统仿真模型可靠,可运用于甘蔗切割动力学仿真研究和指导室内甘蔗切割模拟试验;海绵橡胶材料可用作模拟土壤抱紧甘蔗的材料,抱紧装置可运用于室内甘蔗切割模拟试验。
At present, the domestic and foreign research on the cutting system of sugarcane harvest machinery mainly concentrates on the cutting damage, cutting energy,affecting factors on the rate of broken biennial root, optimization design of cutter and cutting kinematics simulation of sugarcane.There is no any report about the simulation model research of sugarcane-soil system,but it has important significances an practical calues to establish the simulation model of sugarcane-soil system for cutting dynamics simulation research and instructing the indoor test of sugarcane cutting simulation .
In the paper, taking the Taiwan sugarcane 22# and the paddy soils as the object of study, the density, stalk yield stress of sugarcane, the elastic modulus of sugarcane core and sugarcane periderm are obtained by using the physical testing method.Through the field vibration test and using vibration attenuation method,the vibration acceleration curve of sugarcane and the sugarcane - soil system is obtained ,and the correlation analysis between them is carried out . The simulation model of sugarcane-soil system is established with the finite element analysis software ANSYS/LS-DYNA, and based on the Original physical parameter, reverse simulation tests are repeated by amending its physical parameter with Orthogonal experimentation and systematic parameter reverse technique to obain the simulation vibration acceleration curve.And then, contrast analysis of acceleration curve is carried out between the simulation and the experimental results to obain the parameters in the simulation test which approaches with the actual sugarcane physical property parameters.According to the System parameters provided by the simulation model, the sponge rubber plate and the spongy rubber brings are used to simulate the enclasping effects of hard soil and soft soil on the sugarcane, and then a device is designed and the physical verification is carried out.
The results show that: the average density of sugarcane periderm is 1067kg/m~3, the average of elastic modulus is 194.07MPa, the average of sugarcane core is 41.75Mpa, the breaking stress average of sugarcane stem is 15.34Mpa; The sugarcane and soil stuff are plasticity following model.The parameters for the density of sugarcane is 1067 kg/m~3, the elastic modulus is 1.00 E8Pa, the poisson's ratio is 0.4, the yield stress is 1.50 E7Pa, the tangent modulus is 1.80 E5Pa, the strain rate (c) is 100, the strain rate (p) is 10, and damping is 2; The corresponding parameters of the soft soil is 1910 kg/m~3, 1.00E6 Pa, 0.4, 8.00E5 Pa, 1.00E5 Pa, 41, 6, 0.8, 2.2 respectively; and the corresponding parameters of the hard soil is 1850 kg/m~3, 1.50E6 Pa, 0.35, 8.50E4 Pa, 1.20E5 Pa, 38, 5, 0.7, 2 respectively; the simulation model of sugarcane and sugarcane-soil system are credibility which could be applied in dynamics simulation study of sugarcane cutting and the indoor simulated cutting test of sugarcane; the sponge rubber materials could be used as materials for simulating the enclasping effects of soil on sugarcane, and the tension devices could be used in the indoor simulated cutting test of sugarcane.
研究选取台糖22号甘蔗及其种植的壤土(水稻土)作为研究对象,采用物理试验方法,测得了甘蔗密度,蔗芯、蔗皮的弹性模量和甘蔗茎秆的屈服应力;运用振动衰减法,通过田间振动试验,获得甘蔗和甘蔗—土壤系统的振动加速度曲线,并进行相关分析;采用有限元分析软件ANSYS/LS-DYNA建立甘蔗和甘蔗—土壤系统仿真模型,运用反求技术和正交试验法,以参数初始值为基础,不断修改系统的物理特性参数,进行仿真试验,获取甘蔗—土壤系统仿真振动加速度曲线,并和物理实验测试甘蔗振动加速度曲线对比,获得和实际甘蔗物理特性参数相接近的甘蔗—土壤系统仿真模型的系统参数;根据仿真模型提供的系统参数,选择海绵橡胶板和海绵橡胶带来分别模拟硬土壤和软土壤对甘蔗的抱紧作用,设计甘蔗抱紧装置并进行物理试验验证。
结果表明:蔗皮的密度平均值为1067kg/m~3,弹性模量平均为194.07MPa,蔗芯平均为41.75Mpa,甘蔗茎秆的破坏应力平均为15.34Mpa;甘蔗和土壤材料均为塑性随动模型,其中甘蔗参数为密度1067kg/m~3,弹性模量1.00E8Pa,泊松比0.4,屈服应力1.50E7Pa,切线模量1.80E5Pa,应变速率(c)100,应变速率(p)10,失效应变率0.01,阻尼2;软土对应参数为1910kg/m~3,1.00E6 Pa,0.4,8.00E5 Pa,1.00E5 Pa,41,6,0.8,2.2;硬土对应参数为1850 kg/m~3,1.50E6 Pa,0.35,8.50E4 Pa,1.20E5 Pa,38.5,0.7,2;甘蔗以及甘蔗.土壤系统仿真模型可靠,可运用于甘蔗切割动力学仿真研究和指导室内甘蔗切割模拟试验;海绵橡胶材料可用作模拟土壤抱紧甘蔗的材料,抱紧装置可运用于室内甘蔗切割模拟试验。
At present, the domestic and foreign research on the cutting system of sugarcane harvest machinery mainly concentrates on the cutting damage, cutting energy,affecting factors on the rate of broken biennial root, optimization design of cutter and cutting kinematics simulation of sugarcane.There is no any report about the simulation model research of sugarcane-soil system,but it has important significances an practical calues to establish the simulation model of sugarcane-soil system for cutting dynamics simulation research and instructing the indoor test of sugarcane cutting simulation .
In the paper, taking the Taiwan sugarcane 22# and the paddy soils as the object of study, the density, stalk yield stress of sugarcane, the elastic modulus of sugarcane core and sugarcane periderm are obtained by using the physical testing method.Through the field vibration test and using vibration attenuation method,the vibration acceleration curve of sugarcane and the sugarcane - soil system is obtained ,and the correlation analysis between them is carried out . The simulation model of sugarcane-soil system is established with the finite element analysis software ANSYS/LS-DYNA, and based on the Original physical parameter, reverse simulation tests are repeated by amending its physical parameter with Orthogonal experimentation and systematic parameter reverse technique to obain the simulation vibration acceleration curve.And then, contrast analysis of acceleration curve is carried out between the simulation and the experimental results to obain the parameters in the simulation test which approaches with the actual sugarcane physical property parameters.According to the System parameters provided by the simulation model, the sponge rubber plate and the spongy rubber brings are used to simulate the enclasping effects of hard soil and soft soil on the sugarcane, and then a device is designed and the physical verification is carried out.
The results show that: the average density of sugarcane periderm is 1067kg/m~3, the average of elastic modulus is 194.07MPa, the average of sugarcane core is 41.75Mpa, the breaking stress average of sugarcane stem is 15.34Mpa; The sugarcane and soil stuff are plasticity following model.The parameters for the density of sugarcane is 1067 kg/m~3, the elastic modulus is 1.00 E8Pa, the poisson's ratio is 0.4, the yield stress is 1.50 E7Pa, the tangent modulus is 1.80 E5Pa, the strain rate (c) is 100, the strain rate (p) is 10, and damping is 2; The corresponding parameters of the soft soil is 1910 kg/m~3, 1.00E6 Pa, 0.4, 8.00E5 Pa, 1.00E5 Pa, 41, 6, 0.8, 2.2 respectively; and the corresponding parameters of the hard soil is 1850 kg/m~3, 1.50E6 Pa, 0.35, 8.50E4 Pa, 1.20E5 Pa, 38, 5, 0.7, 2 respectively; the simulation model of sugarcane and sugarcane-soil system are credibility which could be applied in dynamics simulation study of sugarcane cutting and the indoor simulated cutting test of sugarcane; the sponge rubber materials could be used as materials for simulating the enclasping effects of soil on sugarcane, and the tension devices could be used in the indoor simulated cutting test of sugarcane.
引文
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[3]曹望成,薛运风,周巨根,茶树新梢剪切力学特性的研究[J],浙江农业大学学报,1995,21
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[5]赵安庆,袁志华,玉米茎秆抗倒伏的力学机制研究[J],生物数学报,报2003,18(3),31
[6]刘庆庭,甘蔗切割机理[D],华南农业大学,2004
[7]卿上乐,甘蔗收获机单圆盘切割器机理研究[D],华南农业大学,2004
[8]NORBERGOS,MASONSC.Ethephon influence on harvestable yield,grain quality,and lod-ngofcorn,Agronomy Journal,1988,80(5),768-772
[9]CARTERPRLodgingfactors and its prevrentinmaize,crop and Soils,19.85,37(6),8-11
[10]PINTER L,Effect of plant density and plant distribution within the row on grain yield and standing ability for maize,Acta Agronomica l-lung arica,1993,42(3),337-348
[11]M INAMI M,Effects of lodging on dry matter production,grain yield and nu-ifional composition at different growth stages in maize,Japanese Journal of Crop Science,1991,60(1),107-115
[12]HEBERTY,Root lodging resistance in forage maize:Genetic variability of root sestem and aerial part,M aydica,1992,37(2),173-183
[13]N egi S C,The effect of compaction and minimum tillage on corn yields and soil properties[J],T tans A SA E,1990,33(3),744-748.
[14]W ang J.Deformation and failure in wet clay soil:Part 1 stress-stain relationships[J].J A gric Engng Res,1993,54(1),37-55.
[15]Hatibu N,Hettiaratch iD R P,The transition from ductile flow to brittle failure in ansaturated soils[J],J A gric Eng Res,1993,54(4),319-328
[16]Gup ta C P.Dynamic behavior of saturated soil under impact loading[J],Trans A SA E,1993,36(4),1001-1007
[17]Wang J,Deformation and failue in wet clay soil:part 3 element analysis of cutting of wet clay by tines[J],J Agdc Engng Res,1994,58(2),121-131.
[18]Hanson G J,Investigating soil strength and stress-strain indices to characterize erodibitity[J],T rans A SA E,1996,39(3),883-890
[19]W eise G,The application of mohr-coulomb soil mechanics to the design of winged shares[J],J A gric Engng Res,1997,67(3),235-247
[20]李小昱,农业土壤力学及生态环境影响效应的研究展望[J],西北农业大学学报,1998,27,109-112
[21]姬长英,潘君拯,湿软土壤剪切变形机理探析[J],农业工程学报,1994,10
[22]区颖刚,塑性土壤破碎方法的比较,农业工程学报[J],1994,10
[23]区颖刚,塑性土壤的弯曲破碎,农业工程学报[J],1997年,13
[24]林金天,土壤动力特性与节能耕作及机具设计[J],农业机械学报,1996,27
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