基于ANSYS的油罐罐底板厚度优化

基于油罐安全运行的重要性,以某大型油罐为研究对象,从油罐罐底板厚度对应力的影响角度进行分析,对静水压下的油罐展开理论分析,利用ANSYS软件对油罐罐底板展开有限元分析,并与理论计算结果进行比较,从而验证有限元模拟的可行性。再运用ANSYS软件来分析罐底板厚度与其应力的关系,得出罐底板厚度的最优解,这对油罐的结构优化和安全运行具有重要意义。     

混凝土板梁火灾时温度及应力分析

设计桥梁结构受火试验,总结水蒸气迁移、腹板开裂、梁体下挠和混凝土爆裂等四种试验现象.通过有限元模拟研究了爆裂现象对构件温度的影响,对比ANSYS温度模拟结果和试验测试结果,验证ANSYS模拟的可行性,结果表明试验构件底板区域为高温集中区,且从底板至顶板之间存在明显的梯度.利用埋设在梁体内部的传感器侦测梁体的变形以及应力应变规律,并与有限元模拟结果进行了比较,结果表明构件受火试验中截面应变符合平截面假定,火损梁截面纵向受压区主要处在顶底板位置.底板的压应力呈二折线分布,顶板几乎不受高温影响,压应力线性分布.受拉区主要位于腹板区域,受拉范围随温度升高扩大.     

某连续刚构桥径向力荷载作用分析

建立T型刚构桥有限原模型,根据有限元模型计算了变截面箱梁底板下缘由于受到预应力荷载作用引起的径向荷载导致横向截面上产生的拉应力及剪应力,并与常规计算进行对比分析,提出了连续刚构桥设计时应注意的问题。     

基于有限元求解的输电塔上下柱节点分析研究

采用ANSYS有限元分析软件对该节点建立三维有限元模型,进行了静力分析,以得到该类结构体系在静力荷载作用下的受力性能。结果表明：支座底板下加劲肋下部的加强环能有效降低节点区的应力幅值,节点最大应力发生在加劲肋下部的加强环与下柱相交处,并满足强度要求。     

FRP型材拼装箱梁的受力性能研究

FRP型材拼装箱梁是由FRP拉挤型材空心板通过三向连接件、骨状挂钩等销接构件拼装而成的箱梁,具有重量轻、耐腐蚀性能好、施工速度快等突出优点,适用于小跨径公路桥及人行桥.本文采用层合材料壳体单元建立了FRP型材拼装箱梁的有限元模型,对单调静力荷载下箱梁的变形和应力等受力性能进行了研究,并与试验结果进行了对比.在此基础上,开展了11片箱梁的有限元参数分析,重点考察了FRP纤维铺层、箱梁顶、底板宽度以及型材板高度等因素对箱梁跨中挠度和应力的影响.研究表明,FRP型材拼装箱的截面尺寸主要由刚度控制,箱梁具有较大的强度储备;箱梁的顶、底板宽度、型材板壁厚和纵隔板、壁板高度等因素对箱梁的刚度或应力的影响较大,而纤维铺层对箱梁结构刚度的影响较小.     

储罐底板焊接变形机理及控制措施

储罐底板焊接变形是由焊接残余应力引起的。从理论上并利用有限元方法对残余应力进行了半定量分析,给出了施工过程中控制储罐底板焊接变形的主要措施。     

基于I-DEAS的炭素挤压机卡环优化设计

根据炭素挤压机卡环的结构和受力特点,利用有限元分析软件I-DEAS建立卡环零件有限元模型,并进行了静力学的有限元分析计算,分析了卡环零件在最大负荷工作状态下的应力和应变情况,根据结果对卡环零件进行了优化设计.通过优化,卡环零件的重量大大减轻,同时零件最大应力也被控制在一个合理范围内.     

球壳大开孔内伸接管结构应力强度评定

利用有限元分析结果对一台开孔率为 0 .6、内伸接管长度为 2 0 mm的球封头大开孔模型容器进行了应力强度评定 ,给出了应力强度评定方法。     

废热锅炉薄管板的三维机械应力分析

运用有限元分析软件ANSYS,对废热锅炉建立了考虑筒体和换热管影响的管板真正实际结构的三维模型,对其进行机械应力分析,得出管板的变形和应力分布云图.将分析结果进行应力线性化处理,按照JB4732-95<钢制压力容器--分析设计标准>中的应力分类和评定方法对管板进行了评定.     

熔融结晶洗涤塔过滤板的有限元分析

利用ANSYS软件对熔融结晶洗涤塔的主要受力构件——过滤板进行了有限元分析,建立了合理的结构和载荷简化模型.通过有限元分析计算,得到了过滤板的轴向变形和主体应力分布云图,并对过滤板的局部应力和外载荷波动条件下的应力进行了分析.     

Study on the stress distribution and modeling of the stand pipe in a circulating moving bed

The liquid-solid circulating moving bed reactor is a novel one, which consists of two reaction chambers and a particle transport system. Particles move down to the lower reaction chamber from the upper reaction chamber through a coupling standpipe and to the particle transport system through a bottom standpipe, and are then conveyed into the upper reaction chamber through a riser. A stress distribution model based on the equations of continuity and momentum balance in the reactor is established and used for simulations which shows that the stress concentration regions are at the coupling standpipe and the bottom of the regeneration chamber. To reduce the largest stress in the stress concentration regions and to minimize catalyst consumption, the regeneration chamber should be designed to give a low ratio of height to diameter. Zoning diagrams of the flow patterns in the bottom standpipe are proposed and the flow patterns can be readily deduced from the pressure gradient.     

钢包底工作衬的热应力分布及结构优化

运用有限单元法 ,计算了几种典型的钢包包底结构的应力分布。计算结果表明 :整体浇注式包底的应力水平比砌筑式包底的高 ;包底工作层增加中档预制件可有效降低包底应力水平。在此基础上 ,提出了一种优化后的包底结构。计算结果和现场试验表明 ,优化后的包底结构降低了包底的热应力 ,提高了包底工作层的使用寿命     

Simulation of Pipeline Slurry Flow under Conditions of Granular Phase Ablation

A model of granular flow in the regime of a moving bed under conditions of granular phase ablation is developed. The model is based on the well‐known two‐layer representation of stratified slurry flow, which assumes a dynamic equilibrium between the bottom (granular) layer and the upper layer of solids‐liquid suspension. The mass transfer rate from the bottom layer to the upper one is defined on the basis of digestion model for a single spherical lump. The model developed allows estimation of the lengths required for the total digestion of lumps in a moving bed and the axial pressure gradient distribution for different flow regimes.     

Bottom design of carbonated soft drink poly(ethylene terephthalate) bottle to prevent solvent cracking

The use of a petaloid shape for the bottom design for carbonated PET bottles is widespread. Through this study, the causes of bottom cracking were investigated and a novel petaloid bottom was designed. The variations of the physical properties of PET according to the stretch ratio were examined and the stretch ratios in the blown bottle were analyzed. Cracking phenomena of the bottom were observed by a solvent‐cracking test. The effective stress and the maximum principal stress in a carbonated bottle were analyzed by computer simulation. It was concluded that the bottom crack occurs because of not only the insufficient strength of material due to the insufficient stretch of PET but also to the coarse design of the petaloid shape. The highest maximum principal stress occurred at the valley in the petaloid bottom of the bottle and this strongly affected the cracking in the bottom. The petaloid shape was redesigned to minimize the maximum principal stress, and this resulted in increasing the crack resistance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1145–1152, 2003     

250吨转炉底吹对熔池搅拌的影响研究

采用物理模拟和数值模拟,研究了某钢厂250 t转炉底吹对熔池混匀时间、气液两相区速度、熔池低速区体积、炉底剪切力和气体能量利用率的影响。结果表明,熔池混匀时间随底吹气量增大而减少,随底吹孔数增加而减少。底吹孔数为12个时,底吹气量由15 L/min增至50 L/min,熔池混匀时间降低54.8%。底吹气量不变(50 L/min),底吹孔数由12个减至3个时,混匀时间增加52.9%。底吹枪数量减少,搅拌区域减小,熔池中“死区”和“低速区”体积比分别增加4.89%和28.9%。底吹枪减至3个时,单个底枪气量增大,气液两相区最大速度由0.34 m/s增至0.64 m/s,底吹孔处炉底所受剪切力增大52%,对炉底耐材寿命不利。从数值模拟结果也可发现,底吹工况的变化影响气体在熔池中的利用效率。底吹总气量增大时,熔池动能增加,但气体能量利用率降低。底吹气量较小时,底吹孔数的变化对气体能量利用率影响较小。底吹气量较大(50 L/min)时,相比于12个底吹孔,6个和3个底吹孔的气体能量利用率分别下降18.4%和23.3%。     

Energy criterion for modelling creep rupture of high-density polyethylene

A technique involving the use of a three-element mechanical model with a critical stored energy criterion modelled accurately the creep rupture time of two types of high-density polyethylene (HDPE) specimens. The upper stress limit where the specimen ruptured immediately on application of load and the lower stress limit where the specimen sustained the load indefinitely were also features of the model. These two limits were found to depend on the resilience, elastic modulus and anelastic modulus of the HDPE.     

STRUCTURE OPTIMIZATION OF A CIRCULATING MOVING BED REACTOR

A stress distribution model for a liquid-solid circulating moving bed reactor that consists of a bottom reaction chamber, a top regeneration chamber, a coupling standpipe, a particle transportation system, and a bottom standpipe is established based on the equations of continuity and momentum balance. Simulations show that the stress concentration regions are at the bottom of the regeneration chamber and the coupling standpipe. To reduce the maximal stress and increase the operation flexibility in a reactor for the 2000-ton-per-year production of linear alkylbenzene, the regeneration chamber should have a low height-to-radius ratio (about 9), a suitable half-conical angle between 28° and 35°, and standpipe radius of about 0.05 m.     

STRUCTURE OPTIMIZATION OF A CIRCULATING MOVING BED REACTOR

A stress distribution model for a liquid-solid circulating moving bed reactor that consists of a bottom reaction chamber, a top regeneration chamber, a coupling standpipe, a particle transportation system, and a bottom standpipe is established based on the equations of continuity and momentum balance. Simulations show that the stress concentration regions are at the bottom of the regeneration chamber and the coupling standpipe. To reduce the maximal stress and increase the operation flexibility in a reactor for the 2000-ton-per-year production of linear alkylbenzene, the regeneration chamber should have a low height-to-radius ratio (about 9), a suitable half-conical angle between 28° and 35°, and standpipe radius of about 0.05 m.     

Model development and validation: Co-combustion of residual char, gases and volatile fuels in the fast fluidized combustion chamber of a dual fluidized bed biomass gasifier

A one-dimensional steady state model has been developed for the combustion reactor of a dual fluidized bed biomass steam gasification system. The combustion reactor is operated as fast fluidized bed (riser) with staged air introduction (bottom, primary and secondary air). The main fuel i.e., residual biomass char (from the gasifier), is introduced together with the circulating bed material at the bottom of the riser. The riser is divided into two zones: bottom zone (modelled according to modified two phase theory) and upper zone (modelled with core-annulus approach). The model consists of sub-model for bed hydrodynamic, conversion and conservation. Biomass char is assumed to be a homogeneous matrix of C, H and O and is modelled as partially volatile fuel. The exit gas composition and the temperature profile predicted by the model are in good agreement with the measured value.     

The service of periglase-chromite refractories in the bottom of a converter with combined blowing

Conclusions Without the use of guniting and effective buildup of a crust the life of a converter bottom lining under the conditions of Nizhnii Tagil Metallurgical Combine does not exceed 400–450 heats.Unstable life (150–300 heats) of the upper layer of the bottom lining is an indication of irrational heating up of the converter before service.As follows from the experimental heats, to increase the life of the area near the tuyeres and the joint of the converter bottom and wall linings it is necessary to use BPGK-72-12 periclase-carbon blocks.Translated from Ogneupory, No. 4, pp. 48–50, April, 1990.