箱式路面体系车辆通过性机理分析

为了评价机械化路面器材对车辆安全通行的保障能力，根据箱式路面器材的结构和受力特点进行结构简化，探讨铰接箱式路面体系与土壤相互作用模型。在沉陷计算的基础上分析集中载荷和均布载荷条件下行驶阻力和挂钩牵引系数的计算公式，提出铰接箱式路面体系车辆通过性评判方法，分析了附着系数、地基参数、结构尺寸对路面器材车辆通过性的影响。     

Estimation and evaluation of dynamic properties as indicators of changes on soil structure in sugarcane fields of Sao Paulo State – Brazil

The indiscriminate management and use of soils without moisture control has changed the structure of it due to the increment of the traffic by agricultural machines through the years, causing in consequence, a soil compaction and yield reduction in the areas of intensive traffic. The purpose of this work was to estimate and to evaluate the performance of preconsolidation pressure of the soil and shear stress as indicators of changes on soil structure in fields cropped with sugarcane, as well as the impact of management processes in an Eutrorthox soil structure located in Sao Paulo State. The experimental field was located in Piracicaba's rural area (Sao Paulo State, Brazil) and has been cropped with sugarcane, in the second harvest cycle. The soil was classified by EMBRAPA [EMBRAPA, 1999. Centro Nacional de Pesquisa de Solos. Sistema Brasileiro de Classificação de Solos, Embrapa, Brasília, 412 pp.] as an Eutrorthox. Undisturbed samples were collected and georeferenced in a grid of 60 m × 60 m from two depths: 0–0.10 m (superficial layer – SL) and in the layer of greatest mechanical resistance (LGMR), previously identified by cone index (CI). The investigated variables were pressure preconsolidation (σ_p), apparent cohesion (c) and internal friction angle (). The conclusions from the results were that the SLSC was predicted satisfactorily from σ_p as a function of soil moisture; thus, decisions about machinery size and loading (contact pressures) can be taken. Apparent cohesion (c), internal friction angle () and the Coulomb equation were significantly altered by traffic intensity. The σ_p, c and maps were shown to be important tools to localize and visualize soil compaction and mechanical resistance zones. They constitute a valuable resource to evaluate the traffic impact in areas cropped with sugarcane in State of Sao Paulo, Brazil.     

3WZ-700型果园喷雾机通过性能分析

针对现代果园低矮密植的园艺特征和果园喷雾机重心动态变化特点,通过试验和建立数学模型对大容量药箱的果园喷雾机的通过性能进行分析,得出药量与越障高度的关系曲线。在0～200 L药量区间内前轮越障由200 mm下降到84 mm;在200～400 L药量区间内前轮越障高度随药量变化缓慢,由84 mm下降到53 mm;后轮越障高度与喷雾机参数无关。实地测试表明,试验均值与理论值基本一致,喷雾机通过性能较好。     

小型沙生灌木收割机通过性及对沙地影响的试验研究

介绍了所设计的小型自行式沙生灌木收割机的总体结构,用以解决科尔沁沙地灌木收割问题。在科尔沁沙地进行了该机器的通过性能研究,将机器反复通过前后对沙土坚实度的影响作为割灌机在沙地通过性能的评价指标,得出该割灌机的牵引力系数与滑转率的关系曲线。试验表明,该割灌机在沙地有较好的通过性能,能满足灌木收割的需要;反复通过同一车辙后,沙土坚实度基本不发生变化,即不对地表植被造成破坏。     

骆驼越沙机理初步分析

本文分析了驼体和驼足对沙地的适应性,借助微细动作分析仪,进行了骆驼沙地运动动作剖析及驼足与沙相互作用研究,初步揭示了骆驼高越沙功能的机理。     

Prediction of trafficability and workability from soil moisture deficit

The relationship between the strength of field soils, under grass ley and winter wheat, and soil moisture deficit has been monitored over an 18 month period. The soil types selected represent a range of agricultural soils commonly found in Europe. Strong correlations were found to exist between moisture deficit and penetration resistance. This relationship has been used to develop a technique for predicting the average number of days on which land at a given site can be trafficked or worked during a year.     

WTC5120TSM型工程车辆沙漠通过能力的研究

以我国西北部沙漠为样地测定了沙土的物理-力学性质,以WTC5120TSM沙漠车为对象进行了沙漠通过性的研究,给出了切线牵引力和行驶阻力的计算公式,以挂钩牵引力和牵引性系数作为通过性的评价指标。研究表明,WTC5120TSM沙漠车在该沙漠中有较好的通过性能,能够满足交通运输作业的要求。本文的研究方法还可以预测WTC5120TSM沙漠车能否在其它沙漠地区完成行走作业。