内胆编织袋全自动绕口焊接机组

本文介绍了一种内胆编织袋全自动绕口焊接机组,其中,输送上料系统输送内胆编织袋至夹送皮带工位;内胆外袋齐边预焊接系统将编织袋内胆与编织袋外袋对齐后进行焊接;折边绕口预压系统对内胆编织袋进行内折边绕口,并完成下压;撑袋整体焊接系统将编织袋内胆和编织袋外袋撑起至紧密贴合并完成整体焊接;下料收集系统将内胆编织袋收集至成品收集装置内,实现内胆编织袋的收集。通过本发明的技术方案,实现了内胆编织袋的齐边预焊接、折边绕口预压、撑袋整体焊接和下料收集的机组自动过程,自动化程度高,整个过程不需要人工参与,且定位准确,产品的质量稳定,提高了产品的成品率。     

纳米高分子材料太阳能热水器内胆问世

纳米高分子材料内胆,就是太阳能热水器产业与化工新材料产业交合,引入先进技术的探索、革新之结果;代替不锈钢内胆,具备“水质洁净、健康耐用”特性;一次性中空成型;材料环保;降低生产制造成本,市场前景好。     

苏泊尔电炖锅不到一个月内胆龟裂

杭州的郑先生日前向媒体投诉称,不久前,自己在超市购买了一只苏泊尔DKZ25A 200电炖锅。用了还不到一个月,陶瓷内胆就出现龟裂现象,拨打客服热线,被告知内胆不能保修。郑先生觉得龟裂是在正常煲汤的情况下出现的,应该是质量问题,不保修说不过去。     

LNG低温贮罐底部内胆封头裂纹研究

在能源结构的转变及能源供应、储备的需要背景之下,大型预应力混凝土常压液化天然气(LNG)储罐在我国的建造日益兴起,双层真空绝热结构的承压LNG低温贮罐亦随之推广。而在具体使用过程中,一些LNG设备会在制作、运输以及使用过程中受到环境等因素的影响发生腐蚀开裂,严重影响其后期的使用。本文结合案例,对裂纹试样化学成分及力学性能进行分析,并对结果进行了讨论,以期为同类项目研究提供参考。     

电磁电饭锅内胆材料技术的发展现状

随着人们生活质量的提高以及电饭锅行业技术的不断创新,电磁加热电饭锅正在逐步取代传统的电阻加热电饭锅。近年来,中国人天价抢购日本电磁电饭锅掀起了高档电饭锅研制的热潮。内胆作为电饭锅的关键部件,是决定电饭锅品质的核心要素,选择合适的内胆材料,对电饭锅内胆的导热性、稳定性和安全性都具有十分重要的影响。综述了国内外电磁电饭锅行业的发展现状,简要介绍了电磁电饭锅的加热原理。按照内胆材料的种类,重点总结了常见电磁电饭锅内胆的制造工艺和应用特点,并对电磁锅陶瓷内胆的应用进行了展望。     

IBC 内胆型坯初始尺寸预测与试验

目的鉴于壁厚控制的复杂性,建立基于有限元型坯尺寸的预测方法。方法采用WorkbenchPOLYFLOW分析软件模拟型坯吹胀的过程,获得均匀的型坯尺寸吹胀成型的IBC内胆壁厚分布;分析型坯初始尺寸对制件最终壁厚分布的影响;确定制件壁厚的薄弱部位及其相对应的型坯位置;调整型坯轴线方向控制点的初始尺寸,获得改善制件最终壁厚的型坯轴线方向的初始壁厚曲线。结果该曲线仿真壁厚极差为2.27 mm,通过大型中空成型机试生产,确定了型坯初始壁厚实验曲线,验证了预测型坯曲线的正确性。结论该尺寸预测方法缩短了生产周期,准确性高,具有较好的实际应用价值。     

复合材料压力容器含凹陷内胆屈曲的有限元分析

提出了一种复合材料压力容器含凹陷金属内胆屈曲的三维有限元分析方法。基于平面应变假设，建立了含凹陷半圆环收缩屈曲分析模型，通过修改有限元模型中内胆的节点坐标，将内胆初始凹陷引入模型中，采用非线性迭代法逐步增大面内载荷，实现了含凹陷半圆环的收缩屈曲分析。在此基础上，建立复合材料压力容器含凹陷内胆的三维有限元分析模型，同时考虑自紧工艺后内胆残余应力的环向分量与轴向分量，实现了复合材料压力容器自紧工艺后含凹陷内胆的屈曲分析。以130 L球形封头薄壁铝合金内胆全缠绕复合材料压力容器为例，分析了含凹陷内胆的临界屈曲载荷以及屈曲发生时内胆的应力及变形。结果显示，含初始缺陷的内胆在自紧工艺之后屈曲模式为局部屈曲；初始凹陷深度越大，临界屈曲载荷越低；与直筒段中部的距离为凹陷轴向宽度1/2的区域和直筒段靠近封头的金属内胆区域存在凹陷易发生屈曲，是金属内胆的薄弱环节。     

铝内胆碳纤维全缠绕气瓶铺层设计

铝内胆碳纤维全缠绕气瓶的铺层设计主要基于网格理论,但该方法仅能得出满足爆破强度的参数,不能满足对铝内胆疲劳性能的要求,因而难以适应气瓶产品的设计需要.将网格理论与铝合金S-N曲线结合,提出一种基于铝合金疲劳寿命设计纤维缠绕层厚度的新方法.依据该方法给出的缠绕层厚度构建有限元模型,通过数值模拟确定合理的自紧力,计算不同载荷下的气瓶应力分布,根据爆破试验数据,利用有限元模型预测气瓶的爆破强度、失效位置及失效形式.结果 表明:该设计方法可便捷地得出满足性能要求的气瓶缠绕层厚度;自紧力合理值可根据设计预期通过有限元分析得出;疲劳载荷下的缠绕层应力设计值与模拟值,偏差在允许范围内;运用该方法设计的气瓶能够同时满足疲劳和爆破性能指标,且失效位置、纤维应力比也符合标准规定.     

高压氢气瓶铝制内胆交流电磁场检测技术

高压全缠绕铝内胆氢气瓶是氢气储运的重要设备,由于材料及结构的限制,常规检测方法难以实现对其铝制内胆的检测。基于交流电磁场检测技术,通过制备铝制内胆试样,并加工不同类型缺陷,进行检测研究。结果表明,交流电磁场技术能够实现对铝制内胆多种类型缺陷的检测,灵敏度及分辨率较好,但缺陷方向对检测效果影响较大,在实际检测中,应根据损伤模式确定检测方向。     

低温容器内胆及压带热应力应变分析及计算

以立式粉末真空绝热低温容器为例,分析了吊压带支承结构静不定系统的热应力和应变协调关系,以及压带和内胆壳壁上增加的附加应力。图4。     

截顶辅助药型罩对椭球罩射流成型影响研究

为了研究截顶辅助药型罩的结构参数对椭球罩射流成型及侵彻性能的影响,运用仿真软件Autodyn-2D的Euler算法对其有限元模型进行数值模拟计算.结果表明:当辅助药型罩高度为2.5mm,直径为15mm时,截顶椭球罩形成的杆式射流具有最优的形态及侵彻性能,使用优化后的辅助药型罩结构侵彻混凝土靶板时,头部速度提升23.9％...     

轴瓦类零件的CAPP系统开发

本文介绍了一套适用于轴瓦行业的CAPP系统。叙述了基于工序代码优先数和工艺决策自动生成轴瓦类零件的加工工艺以及基于GT代码和工序图特征图形要素库自动生成轴瓦零件加工工序图的方法。     

Failure analysis of an aero-engine combustor liner

The paper presents a failure case of an aero-engine combustor liner. Macroscopic and microscopic observations, microstructure investigation, chemical analysis and hardness measurement have been performed to investigate the damage mechanism and failure causes of notches and cracks. The results show that the failure modes of notches, axial-direction crack along the combustor liner and crack at the edge of welding spot are respectively attributed to high-temperature ablation, mixed crack of ablation and thermal fatigue crack. The bad configuration of crossover tube is the main reason for the failure of combustor liner.     

Filament-wound pressure vessel with thick metal liner

A method for calculating stress and strain in non-symmetric filament-wound pressure vessels with thick metal liners, up to burst pressure, is presented. The calculations are based on classical laminate theory and Tsai-Wu failure criterion. Plastic yielding of the liner and transverse cracking of the composite are not considered failures of the vessel and are modelled by reduced properties. The effect of changing thicknesses of various layers, on burst pressure and efficiency of the vessel, is considered. It is shown that the efficiency of a thick liner reinforced with filament winding can approach optimal values that are quoted in the literature, even when the liner is selected arbitrarily. The calculations agree with test results of two 6 litre vessels having the same liner: one with Kevlar 49/Epoxy overwrap and the other with T300 Carbon/Epoxy.     

Fracture toughness of liner board evaluated by theJ-integral

TheJ-integral approach to characterizing the fracture toughness of liner board is investigated. Three methods, namely the single-specimen, multiple-specimen and Liebowitz non-linear energy method are evaluated in terms of accuracy and convenience in the fracture toughness determination. The multiple-specimen and Liebowitz methods yield consistent fracture toughness values that are independent of crack length, while the single-specimen method yields toughness values that depend on crack length. In terms of convenience the Liebowitz methods is superior to the multiple-specimen method since it requires fewer specimens and employs a data reduction methodology that is easily implemented.     

Failure analysis of thin spray-on liner coated rock cores

Thin spray-on liners (TSLs) are surface support materials used in mining and civil engineering projects since 1990s with a wide ranging area of application from bolt/mesh support replacement to pillar reinforcement systems. This study presents the investigation of pillar reinforcement capacity of the TSL coated andesite rock core by compression test to mimic pillar reinforcement effect. The uniaxial compressive strength (UCS), modulus of elasticity (E), and energy absorbance capacity of uncoated and 5 mm coated cores having 25, 55, 75, and 100 mm diameters were compared. It was observed that there was no significant improvement in strength or stiffness for the homogenous rock cores coated with < 20% (TSL thickness to core diameter ratio) coverage. The main reinforcement contribution of the TSL was observed on post-failure region of the compression tests. Coated samples had higher energy absorbance (toughness) values than uncoated ones while the coverage of the TSL was increased, toughness enhancement also increased. Therefore, pillar reinforcement capacity of a TSL is a function of both pillar diameter and the TSL thickness. A new equation was found between energy absorbance gain for a given core dimeter and the coated TSL thickness. Researches or design engineers can use this equation as a guide to quantify the energy absorbance gain for a given pillar dimension and TSL thickness. It was found that the common on-site TSL practice of application of a fixed thickness (3–5 mm) for a given diameter does not contribute the toughness enhancement or pillar reinforcement.     

Microstructural examination of service exposed coal mill liner material

This study mainly focuses the microstructural characterisation of the service exposed coal liner. These liners are generally referred to as bull ring segments in the bowl mill of coal pulveriser systems. The failed bull ring segment was collected from a coal-fired power plant of Kolaghat thermal plant, West Bengal, India. The crack that has been observed in the middle of the liner was observed under SEM and detailed microstructural studies are made for the liner material. The hardness measurements are made and XRD is carried out to identify the phases present in the sample. The results suggest that the material confirms to high chromium cast iron and microstructural studies reveal that the cracks are mainly due to the heavy service exposed conditions where lumps of coal and silica sand falling on these liners causing severe impact and abrasion conditions. High abrasive studies on the liner material are carried out and it showed that increasing the abrasive size as well as load is responsible for higher wear loss. The results suggest that prolonged exposure to abrasion conditions results in the progressive removal of the matrix material and due to various phase transformations from austenite to martensite introduces surface volume changes and causes the generation of cracks and further lead to failure of the component.     

超薄金属内衬复合材料压力容器的结构分析

采用有限元方法对超薄金属内衬复合材料压力容器结构进行分析。在分析中, 几何模型中的封头段考虑了复合材料铺放角度和厚度沿平行圆半径变化, 材料模型中的复合材料层和内衬层分别选用复合材料层合板理论和弹塑性理论进行分析, 二者之间的界面变形协调性及不可贯入性引入接触分析进行考虑。数值结果表明:在工作压力下, 容器复合材料层纵向应变均为拉应变, 环向存在部分压应变, 内衬层发生塑性变形; 卸载后, 容器的复合材料层处在拉应力状态, 内衬层处在压应力状态。在此基础上, 利用容器的简化模型, 根据内衬层最大变形点荷载位移曲线实现了容器内衬层局部屈曲模拟。容器水压应变测试和内衬局部屈曲观测结果与数值模拟结果吻合较好, 验证了本文中分析的可靠性。