EXPERIMENTAL STUDY ON INFLUENCE OF SUPPLIED PRESSURE FLUCTUATION ON OUTPUT ARACTERISTIC OF PRESSURE CONTROL SYSTEM OF ROLLING MILL

ＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＩＮＦＬＵＥＮＣＥＯＦＳＵＰＰＬＩＥＤＰＲＥＳＳＵＲＥＦＬＵＣＴＵＡＴＩＯＮＯＮＯＵＴＰＵＴＡＲＡＣＴＥＲＩＳＴＩＣＯＦＰＲＥＳＳＵＲＥＣＯＮＴＲＯＬＳＹＳＴＥＭＯＦＲＯＬＬＩＮＧＭＩＬＬ①ＺｈａｏＪｉｎｇｙｉＬ...     

STUDY ON USING SERIAL PIPE TO IMPROVE THE DYNAMIC RESPONSE OF ELECTRO－HYDRAULIC SPEED CONTROL SYSTEM

ＳＴＵＤＹＯＮＵＳＩＮＧＳＥＲＩＡＬＰＩＰＥＴＯＩＭＰＲＯＶＥＴＨＥＤＹＮＡＭＩＣＲＥＳＰＯＮＳＥＯＦＥＬＥＣＴＲＯ－ＨＹＤＲＡＵＬＩＣＳＰＥＥＤＣＯＮＴＲＯＬＳＹＳＴＥＭＳＴＵＤＹＯＮＵＳＩＮＧＳＥＲＩＡＬＰＩＰＥＴＯＩＭＰＲＯＶＥＴＨＥＤＹＮＡＭ...     

EXPERIMENTAL STUDY ON OPEN－DIE COLD EXTRUSION FORMING TECHNIQUE FOR INVOLUTESPLINE SHAFTS

ＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＯＰＥＮ－ＤＩＥＣＯＬＤＥＸＴＲＵＳＩＯＮＦＯＲＭＩＮＧＴＥＣＨＮＩＱＵＥＦＯＲＩＮＶＯＬＵＴＥＳＰＬＩＮＥＳＨＡＦＴＳＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＯＰＥＮ－ＤＩＥＣＯＬＤＥＸＴＲＵＳＩＯＮＦＯＲＭＩＮ...     

EXPERIMENTAL STUDY ON LUBRICATION BEHAVIOR OF DOUBLE ENVELOPING HOUK GLASSWOKM GEARING

ＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＬＵＢＲＩＣＡ－ＴＩＯＮＢＥＨＡＶＩＯＲＯＦＤＯＵＢＬＥＥＮＶＥＬＯ－ＰＩＮＧＨＯＵＫＧＬＡＳＳＷＯＫＭＧＥＡＲＩＮＧＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＮＬＵＢＲＩＣＡ－ＴＩＯＮＢＥＨＡＶＩＯＲＯＦＤＯＵＢＬＥ...     

ANALYSIS OF ROLLING BY ELASTO-PLASTIC FINITE DEFORMATION CONTACT BOUNDARY ELEMENT METHOD

ＡＮＡＬＹＳＩＳＯＦＲＯＬＬＩＮＧＢＹＥＬＡＳＴＯＰＬＡＳＴＩＣＦＩＮＩＴＥＤＥＦＯＲＭＡＴＩＯＮＣＯＮＴＡＣＴＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＭＥＴＨＯＤＨｕａｎｇＱｉｎｇｘｕｅＳｈｅｎＧｕａｎｇｘｉａｎＸｉａｏＨｏｎｇＴａｉｙｕａｎＨｅａｖｙＭａ...     

CALCULATION AND EXPERIMENTAL INVESTIGATION OF ELECTRIC FIELDS INDUCED BY ELECTRODES IN ELECTROSTATIC CHARGED POWDER SPRAYING TECHNIQUE

ＣＡＬＣＵＬＡＴＩＯＮＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＥＬＥＣＴＲＩＣＦＩＥＬＤＳＩＮＤＵＣＥＤＢＹＥＬＥＣＴＲＯＤＥＳＩＮＥＬＥＣＴＲＯＳＴＡＴＩＣＣＨＡＲＧＥＤＰＯＷＤＥＲＳＰＲＡＹＩＮＧＴＥＣＨＮＩＱＵＥＣＡＬＣＵＬ...     

THREE DIMENSIONAL ELASTO-PLASTIC CONTACT BOUNDARY ELEMENT ANALYSIS FOR ROLLING WITH CONSIDERATION OF FRICTION

ＴＨＲＥＥＤＩＭＥＮＳＩＯＮＡＬＥＬＡＳＴＯＰＬＡＳＴＩＣＣＯＮＴＡＣＴＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＲＯＬＬＩＮＧＷＩＴＨＣＯＮＳＩＤＥＲＡＴＩＯＮＯＦＦＲＩＣＴＩＯＮ①ＸｉａｏＨｏｎｇＣｈｅｎＹｉｍｉｎｇＳｈｅｎＧｕａｎｇ...     

3D RIGID－PLASTIC FINTEELEMENT ANALYSIS OF BACKWARD SPINNING OF CYLINDRICAL WORKPIECE

３ＤＲＩＧＩＤ－ＰＬＡＳＴＩＣＦＩＮＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＯＦＢＡＣＫＷＡＲＤＳＰＩＮＮＩＮＧＯＦＣＹＬＩＮＤＲＩＣＡＬＷＯＲＫＰＩＥＣＥ３ＤＲＩＧＩＤ－ＰＬＡＳＴＩＣＦＩＮＴＥＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＯＦＢＡＣＫＷＡＲＤＳＰＩＮＮ...     

THEORETICAL ANALYSIS AND EXPERIMENTAL INVESTIGATION OFTHE INFLUENCE OF BEARINGMISALIGNMENT ON STABILI

ＴＨＥＯＲＥＴＩＣＡＬＡＮＡＬＹＳＩＳＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＴＨＥＩＮＦＬＵＥＮＣＥＯＦＢＥＡＲＩＮＧＭＩＳＡＬＩＧＮＭＥＮＴＯＮＳＴＡＢＩＬＩＴＹＯＦＲＯＴＯＲ－ＢＥＡＲＩＮＧ　ＳＹＳＴＥＭＨｕａｎｇＷｅｎｚｈ...     

TEMPERATURE FIELD CONTROL PRINCIPLE AND CONTROL MODELS FOR CRYOGENIC MACHINING SYSTEM

ＴＥＭＰＥＲＡＴＵＲＥＦＩＥＬＤＣＯＮＴＲＯＬＰＲＩＮＣＩＰＬＥＡＮＤＣＯＮＴＲＯＬＭＯＤＥＬＳＦＯＲＣＲＹＯＧＥＮＩＣＭＡＣＨＩＮＩＮＧＳＹＳＴＥＭＴＥＭＰＥＲＡＴＵＲＥＦＩＥＬＤＣＯＮＴＲＯＬＰＲＩＮＣＩＰＬＥＡＮＤＣＯＮＴＲＯＬＭＯＤＥＬＳＦＯ...     

An Engineering Model for Three-Dimensional Elastic-Plastic Rolling Contact Analyses

Fatigue life of heavily loaded rolling bearings is strongly dependent on elastic-plastic material properties. For bearing steels these elastic-plastic properties can be accurately obtained by performing monotonic or half-compressive tests. A three-dimensional strain deformation analysis based on the incremental theory of plasticity and the use of Prandtl-Reuss relations in conjunction with the von Mises yield criterion was developed in order to evaluate the permanent deformation in dry contacts loaded above the elastic limit in case of normal loading. The Ramberg-Osgood stress-strain relation for two martensitically hardened variants of SAE 52100 bearing steel considered the nonlinear kinematic and/or isotropic material behavior. Parameters describing the influence of retained austenite are modeled by using a nonlinear isotropic law. Pressure distribution and contact surface displacements during incremental loading are evaluated by using a conjugate gradient method and the internal stress field is derived by using the superposition principle. Further, a fast analysis of smooth surfaces in elastic-plastic static and rolling contact is developed based on analytical relations for the internal stress field. Cyclic evaluation of plastic strains and residual stresses is carried out until shakedown. In order to verify the theoretical model, rolling contact tests under high normal load were performed. Residual stresses and residual profiles measurements show excellent agreement between numerical and measured cyclic values.     

箱形类金属结构弹塑性控制设计的理论与方法

在理论与实验研究的基础上，阐述箱形类金属结构的弹塑性控制设计在保证结构的强度，刚度和稳定性的前提下提高结构承载能力的原理，给出了弹塑性控制设计的基本计算方法。     

A comparative computational investigation on the effects of randomly distributed general corrosion on the post-buckling behaviour of uniaxially loaded plates

Post-buckling behaviour and ultimate strength of imperfect corroded steel plates used in ships and other related marine structures are investigated. Nonlinear elastic-plastic large deflection finite element analyses are performed on corroded steel plates. General corrosion wastage is considered to be distributed randomly on either one or both surfaces of the analyzed plates. The effects of general corrosion are introduced into the finite element models using a random thickness surface model. The effects of corroded plate parameters on the plate post-buckling and ultimate strengths are evaluated in detail. It was realized that the aspect ratio and thickness (slenderness) of the corroded plates affects their strength characteristics. Age of the plate models affects mainly their post-buckling-strength regimes and degrades their buckling/ultimate strength. Also, nonlinear post-buckling characteristics of the plates suffering either one-side or both-side random corrosion exhibit some differences. Finally, simple empirical formulations are proposed in order to give rough estimations of the ultimate strength of randomly corroded plates.     

大吨位自卸车货厢高强度钢板强度等代设计

对大吨位自卸车货厢高强度钢板等代设计问题进行了研究,以弹性力学和板壳理论为基础,推导出利用高强度钢板进行强度等代设计时板厚的计算公式,给出了具体的等代设计流程图,并对大吨位货厢进行了轻量化设计。在不改变货厢原结构情况下,实现了货厢减重1679.757kg,约32.95%,取得了较好的轻量化效果。     

Simulation and experiment of secondary contact stiffness of rough surface

Machined surfaces usually need to be loaded several times during assembly. The surface morphology after the simulation loading may be quite different from the physical loading, which subsequently causes differences between the contact stiffness after secondary simulation loading and secondary physical loading results. The fractal theory was used to reconstruct the measured surface morphology, followed by contact stiffness simulation and test. The results show that contact stiffness of new morphology obtained by the first simulated loading using the elastic-plastic deformation theory are smaller than the first loading test results, with an average error of −9.71 %. Contact stiffness of used morphology obtained by the first simulated loading using the pure elastic deformation theory are in good agreements with the second loading test results, with an average error of 4.71 %. However, the average contact stiffness of new morphology obtained by the second simulated loading using the elastic-plastic deformation theory, which is traditionally used for contact analysis, are 2.15 times larger than the second loading test result. These research results demonstrate a feasible finite element method (FEM) for solving the contact problem of rough surfaces that need to be assembled multiple times.

     

新的粗糙表面弹塑性接触模型

提出一种新型的粗糙表面弹塑性微观接触模型.该模型的建立基于接触力学理论和接触微凸体由弹性变形向弹塑性变形及最终向完全塑性变形的转化皆是连续和光滑的假设.研究单个微凸体在载荷逐渐增加时的变形规律,并重点推出弹塑性变形区间的接触方程.在此基础上应用概率统计理论导出了粗糙表面的接触载荷、平均分离和实际接触面积之间的数学关系式.在不同的塑性指数和载荷条件下,该模型与GW弹性模型和CEB弹塑性模型就实际接触面积和法向距离的预测结果进行了对比.结果表明,在同样塑性指数和载荷条件下比GW模型预测的实际接触面积大但法向距离小,且两者的差距随塑性指数和载荷的增加而增大.因此该模型的预测结果更加符合人们的试验观察和直觉,能够更加科学和合理地描述两个粗糙表面的微观和宏观接触状态.     

非标压力机箱形主梁全约束优化设计

根据非标设备结构优化问题的特点,给出满足《钢结构设计规范》(GBJ17 88)规定的箱形主梁全约束优化设计方 法。将编制的内罚函数法优化程序应用于主梁的设计,计算结果表明,该优化方法可应用于实际设计。     

Tooling design in sheet metal forming using springback calculations

A method to design tooling in sheet metal forming using springback calculations is presented. The designed tooling produces a part which matches the desired shape, thereby compensating for springback. To design the appropriate tooling, traction distributions on the sheet in the fully loaded deformed state are computed using the finite element method. The calculated tractions are then used to numerically reproduce springback of the desired part shape by elastic unloading of the part in a reverse manner. The method is examined for materials covering a range of steel strength and hardening, and is found to produce parts with negligible shape error. The success of the tooling design algorithm leads to a proposal for an experimental method to design tooling based on traction distribution measurements.     

Methodology to Estimate Remaining Service Life of Steel Structure by Possibilistic Reliability Theory

Steel structure system of crane deteriorates over time due to environmental effects,material fatigue,and overloading.System structural reliability and remaining service life assessment methods are developed during the few decades.But until now estimating remaining service life methods of crane steel system by reliability theory begin to develop.Safety assessment of existing steel structure system requires the development of a methodology that allows for an accurate evaluation of reliability and prediction of the remaining life.Steel structures are the supporting elements in the special equipment such as hoisting machinery.Structure reliability and remaining service life safe assessment are important for steel structures.For finding the reason which caused the failure modes(such as fatigue strength failure,stiffness failure and stability failure),incremental loading method based on possibilistic reliability is applied into dynamic structure failure path research.Through reliability analyzing and calculating for crane,it is demonstrated that fatigue damage is the most common failure mode.Fuzzy fatigue damage accumulation theory is used for basis theory and Paris-Eadogan equations are used for mathematical modeling.All fatigue parameter values of the welding box girder of bridge cranes are determined and fatigue remaining life formulas are deduced.After field test and collecting working parameters of numerous cranes,typical fatigue load spectrum was compiled for the dangerous point of box girders used in the area.Fatigue remaining life is assessed for different types and lifting capacities.Safety for steel structure system of bridge crane is assessed by two quantitative indexs:reliability and remaining life.Therefore,the evaluation means is more comprehensive and reasonable.The example shows that the two quantitative indexs are mutually correlated.Through analyzing the 120 t-22.5 m bridge crane of a certain enterprise,a new methodology to estimate remaining service life of steel structure by possibilistic reliability theory is introduced for safety evaluation of structure system.     

三维四向编织复合材料接头承载能力分析

针对三维四向编织复合材料单耳承力接头,用细观力学和均匀化方法分析三维编织复合材料的细观结构,用MATLAB程序对复合材料弹性性能进行参数化求解,利用ANSYS估算两种几何尺寸试样的破坏载荷.有限元计算结果与试验值有较好的吻合,显示文中方法可以满足工程设计和分析的要求.