真空高压烧结炉应力分析及疲劳评定

对石油化工企业中常用的真空高压烧结炉卡箍组件结构进行ANSYS应力分析及疲劳评定,通过对结构相关参数的确定,根据GB/150.3标准确定了主要部位的厚度尺寸;结构分析中约束筒体端部轴向位移,对称面施加对称约束;炉盖齿面、齿圈齿面、筒体法兰齿面之间设置为摩擦接触,从而确定应力最大位置,结果评定为合格;根据设备使用年限和循环次数进行了该组件的疲劳分析评定,结果也是合格的。     

真空高压气淬炉齿啮式快开结构应力有限元计算

利用ANSYS中接触单元法 ,采用面 面接触模型对齿啮式快开结构齿间的接触行为进行数值模拟 ,对有限元计算结果选出高应力区进行应力线性化处理 ,应力评定结果表明各应力值均在许用范围之内。采用电阻应变仪测量布点应力 ,实测值与计算值较吻合。     

单层与多层包扎筒体开孔的应力分析比较

对单层与多层包扎筒体开孔接管进行了应力分析,考虑了层与层之间滑动无摩擦接触与有摩擦接触(摩擦系数0.15)两种情况,并对关键路径的薄膜应力、薄膜加弯曲应力以及计算时间进行了比较分析。结果表明,多层包扎结构筒体厚度方向的薄膜应力较小,不连续处的应力较大。在非疲劳条件下,对于高压厚壁容器,推荐使用多层包扎的结构。     

汽爆罐快开齿啮法兰结构的有限元分析

通过面-面接触单元模拟汽爆罐快开齿啮法兰的啮合齿接触过程,运用整体有限元应力分析的方法对汽爆罐快开齿啮法兰结构进行计算与分析,对危险截面进行了强度评定和疲劳分析.     

隐框幕墙中空玻璃结构粘接设计探讨

中空玻璃结构边缘结构胶三面粘接,在相同应力下粘接体的应变远低于两面粘接,对应于相同应变的应力却要高出1倍。保证荷载下隐框幕墙中空玻璃结构粘接体应力不超出强度设计值,必需对荷载、力的传递、粘接体应力分布及应变特点等进行具体分析,在结构粘接设计中给予更多的考虑。     

带补强圈大开孔的压力容器应力分析研究

压力容器由于工艺和结构上的要求,常常需要设置各种大开孔结构,超出了等面积法的适用范围。采用GB 150—2011《压力容器》标准中的方法进行分析时,无法对带补强圈大开孔的压力容器进行补强计算。分别采用标准接触算法和绑定接触算法,利用ANSYS有限元分析软件对带补强圈大开孔接管结构进行应力分析和评定。结果表明,压力容器中带补强圈大开孔接管应力最大值一般分布在接管与筒体连接处,在计算过程中需考虑补强圈与筒体的接触作用,标准接触算法和绑定接触算法得到的计算结果相差不大。     

整体多层包扎式高压容器筒体与球形封头连接区应力状态有限元分析

建立了整体多层包扎式高压容器多层筒体与球形封头连接区有限元接触分析模型,得到了端部阶梯式连接结构的应力分布状况,并与相同尺寸非多层结构的应力分布进行了比较。结果表明,两种结构内外壁应力变化趋势相似,在连接区出现明显的应力集中,连接处轴向应力上升趋势大于周向应力,达到最大应力值后迅速衰减。     

半可燃药筒竖放状态下的应力应变与结构强度分析

针对半可燃药筒在竖向放置过程中可能出现的受力变形问题,建立了力学模型.采用三维非线性有限元理论对药筒的接触变形进行了计算,得到了药筒的应变、应力分布规律和半可燃药筒结构强度的数值预测.结果表明,在竖放无载荷的情况下,筒体在变直径区域产生应力集中,与金属底座的交界处应力最大.半可燃药筒的筒体变形量较大,金属底座各处的变形量几乎为零.筒体与金属底座上的最大应力远小于材料的许用应力,因此筒体结构和金属底座是安全的.     

环氧树脂塑封过程残余应力研究

利用Moldfl ow和Ansys对环氧树脂塑封过程进行模拟,并且用应力偏光仪获得应力条纹,然后与模拟结果进行对比。结果表明,环氧树脂热固性塑料在完成塑封后,其残余应力基本呈均匀分布。然而由于条带和塑封体热膨胀系数不同,在条带和塑封体接触部位会形成应力集中。并发现塑封体的残余应力和塑封体与条带接触部位的最大残余应力会随着保压压力的增大呈线性降低趋势。残余应力的降低不仅能够保证尺寸精度,而且塑封件在使用时还能减少塑封体与条带开裂的可能性。     

基于有限单元法的法兰连接中的接触分析

应用ANSYS软件对法兰接头结构进行建模和网格划分,并且对法兰与螺栓接触处做了非线性接触分析,得到了在设计压力下螺栓结构的应力分布和变形。之后分别对整体模型和螺栓模型做出了应力强度分析。按照JB4732—1995《钢制压力容器-分析设计标准》对危险截面进行应力强度评定。分析结果表明,强度满足要求。     

烧结炉卡箍快开结构强度分析

应用ANSYS软件对烧结炉的主要部分卡箍快开结构进行模型建立和网格划分,并且在卡箍齿与上下法兰啮合处做了接触分析,根据设计条件进行了热-力耦合分析。依据JB4732-1995《钢制压力容器—分析设计标准》对危险截面进行应力强度评定。分析结果表明,强度满足要求。     

大直径卡箍结构的刚度分析

在大直径卡箍结构设计实例的基础上,利用有限元分析软件获取与刚度相关的成组数据,讨论了各参数的变化对卡箍结构刚度的影响,为今后类似结构的设计提供依据.     

利用加强筋单元分析子午线轮胎的结构

根据10．00 R20型全钢载重子午线轮胎的实际结构,考察了轮胎的材料非线性、接触非线性以及大变形等力学特性,利用加强筋单元模拟了钢丝帘线／橡胶复合材料,建立了子午线轮胎的非线性有限元分析模型,分析了轮胎在充气压力及垂直栽荷下接地印痕上的压力分布、剪应力、摩擦应力、接触及变形情况。结果表明,轮胎静态接地印痕上的压力分布是不均匀的,压力分布呈中部小、两端高的马鞍形;剪应力分布也不均匀,在胎肩部位剪应力较大;带来层边缘应变能密度较大。     

The Effects of High Contact Pressures and Temperatures on the Adhesion of Amorphous Polystyrene to Borosilicate (Pyrex) Glass

The effects on adhesive joint strength of four pressure-temperature histories, each over the range of pressures from 1 to 1500 bars and temperatures from 25 to 200°C, has been investigated with polystyrene-Pyrex glass butt joint specimens. The various pressure-temperature histories were designed to show the separate effects of permanent stresses, transient stresses and interfacial contact on joint strength. This strength increased as the number of stress concentration loci were reduced through application of high contact pressures on the melt. However, isobaric solidification of the polymer led to a maximum in fracture stress as a function of applied molding pressure because of the existence of a critical pressure at which permanent thermal stresses were minimized. A series of isothermal compression-decompression molding operations showed fracture stress to increase with interfacial contact area until maximum contact was achieved. A 100 per cent gain in bond strength was realized when interfacial contact was maximized concurrent with minimizing both the permanent and transient stresses which normally develop when the adhesive joint is formed. Microscopic observations of interfaces in both non-fractured and fractured butt joints established a qualitative relationship between debonding, the mechanism of fracture, and joint strength.     

The Effects of High Contact Pressures and Temperatures on the Adhesion of Amorphous Polystyrene to Borosilicate (Pyrex) Glass

The effects on adhesive joint strength of four pressure-temperature histories, each over the range of pressures from 1 to 1500 bars and temperatures from 25 to 200°C, has been investigated with polystyrene-Pyrex glass butt joint specimens. The various pressure-temperature histories were designed to show the separate effects of permanent stresses, transient stresses and interfacial contact on joint strength. This strength increased as the number of stress concentration loci were reduced through application of high contact pressures on the melt. However, isobaric solidification of the polymer led to a maximum in fracture stress as a function of applied molding pressure because of the existence of a critical pressure at which permanent thermal stresses were minimized. A series of isothermal compression-decompression molding operations showed fracture stress to increase with interfacial contact area until maximum contact was achieved. A 100 per cent gain in bond strength was realized when interfacial contact was maximized concurrent with minimizing both the permanent and transient stresses which normally develop when the adhesive joint is formed. Microscopic observations of interfaces in both non-fractured and fractured butt joints established a qualitative relationship between debonding, the mechanism of fracture, and joint strength.     

The critical stresses of brittle and ductile polymeric particles

This study was undertaken to examine deformation of single, homogeneous brittle and ductile spheres and relate these contact stresses with bulk stresses of the material.Both ductile (polycarbonate) and brittle (polystyrene) polymer particles were measured for critical forces using a Single-Particle Crush Apparatus. Considering the criterion of material fracture, Hertzian analysis was used to c⁼ ompute average critical stresses and critical strass distributions. the micron size particles were compression-molded into cylinders with a length-to-diameter ratio of two, and the critical stresses of the compressed cylinders were determined under plane compression using an Instron at 8 × 10^?3 sec^?1 sec^?1 - Single-particle critical stresses were compared with bulk critical stresses, their average values as well as their distributions.     

硫化钢圈夹具对全钢轮胎硫化胶囊使用寿命的影响

通过力学仿真方法研究硫化钢圈夹具对全钢轮胎硫化胶囊使用寿命的影响。根据轮胎硫化过程中硫化胶囊的受力状态优化钢圈夹具与硫化胶囊的接触面形状后,硫化胶囊使用寿命延长15%~19%,因硫化胶囊裂口引起的废次品率大大降低,提升了轮胎外观质量,同时可减轻劳动强度。     

A phase field model of pressure-assisted sintering

The incorporation of an efficient contact mechanics algorithm into a phase field sintering model is presented. Contact stresses on the surface of arbitrarily shaped interacting bodies are evaluated and built into the model as an elastic strain energy field. Energy relaxation through deformation is achieved by diffusive fluxes along stress gradients and rigid body motion of the deforming particles maintain contact between the particles. The proposed model is suitable for diffusion deformation mechanisms occurring at stresses below the yield strength of a defect-free material; this includes Nabarro-Herring creep, Coble creep and pressure-solution. The effect of applied pressure on the high pressure-high temperature (HPHT) liquid phase sintering of diamond particles was investigated. Changes in neck size, particle coordination and contact flattening were observed. Densification rates due to the externally applied loads were found to be in good agreement with a new theory which implicitly incorporates the effect of applied external pressure.     

高温法兰连接结构的有限元模拟及安全评定

利用ANSYS软件分析了高温螺栓法兰连接系统在预紧、承压及热-机操作工况下的应力和变形行为,并基于强度分析和密封分析对螺栓法兰连接进行了安全评定.结果表明：不同工况下,应力具有相似的分布规律,法兰最大应力在螺母与法兰接触面的内侧,上、下法兰应力分布具有对称性;螺栓应力呈现拉弯组合形变,最大应力出现在由中间向两端第一个螺纹根部;垫片应力在各工况下均呈现为外大内小,密封面压力均大于满足密封要求的最小压紧力,法兰的转角均小于0.3°,满足法兰刚度要求,强度分析和密封分析均满足要求,具有良好的紧密性,给出了一种工程分析方法.     

固态金属锂电池研究进展：外部压力和内部应力的影响

固态锂金属电池具有理论能量密度高、安全性高等优势,是极有前景的下一代储能系统。然而,固体电极与固体电解质之间有限的固–固接触严重阻碍了界面离子的传输。因此,增加外部压力是增加固–固接触及延长电池循环寿命的重要途径。同时,在充放电过程中,电极体积变化产生的内应力也将影响电池界面特性。通过介绍两种基本物理接触模型,结合硫化物、氧化物、聚合物电解质以及金属锂的物理性质,综述了外压和内部应力对电解质、电极及电池的影响。最后,对外压力与内应力在全固态金属锂电池中的作用进行了总结和展望。