共查询到19条相似文献,搜索用时 140 毫秒
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《中国有色金属学报》2019,(10)
本文建立了波导管弯曲分析有限元分析模型,针对6063波导管计算了不同弯曲半径下过渡区域壁厚分布,利用稳定变形区壁厚简化计算公式,得到稳定变形壁厚与弯曲半径关系曲线。对给定波导管(内腔15.8 mm×7.9mm,壁厚1.0 mm)计算了不同弯曲角度下(ρ=40 mm)弯曲外侧壁厚分布,指出小半径弯曲过渡区域可以延伸到30°范围甚至更大。取90°弯曲件进行了壁厚计算值与实验值比较,除去两端10°内急剧变化段,壁厚减薄率误差小于2%。通过对比变形过渡区弧长,确定弯曲过渡区中性层弧长稳定在管材宽度B的1.2倍左右,并依此给出简化的壁厚计算公式。通过计算得出芯棒支撑范围应与过渡变形区范围一致,小半径弯曲时可达到30°角度范围。文中分析了顶推力、摩擦因数、芯棒支撑角度等对壁厚变化的影响规律,并给出了合理计算结果。这些分析计算对指导波导管弯曲研究和生产技术改进提供了重要依据。 相似文献
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采用消失模铸造工艺生产蠕铁排气出口管 总被引:2,自引:0,他引:2
介绍了消失模法生产蠕铁排气出口管的工艺过程.试验发现,采用反直浇道结合侧注的模组形式为佳,每组8件、管口朝下;涂料直接影响铸件表面积碳及皱皮倾向;并采用消失模法批量生产了蠕铁排气出口管,材料性能及金相组织达到要求,铸件壁厚均匀,表面光滑,已用于红旗轿车的部分车型. 相似文献
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螺旋槽管材滚压成形过程的有限元分析 总被引:2,自引:0,他引:2
利用ANSYS有限元分析软件中的LS-DYNA求解器,分别采用球形和带过渡圆弧的三角形滚压辊,对螺旋槽管材滚压成形过程进行了数值模拟,得到了应力和应变分布规律、金属变形流动规律以及滚压力大小.根据有限元计算结果,分析了不同辊型的滚压辊和螺旋槽管的主要结构参数对滚压力的影响规律以及螺旋凹槽处壁厚的变化规律.通过试验验证了用有限元法进行螺旋槽管材滚压成形过程数值模拟的可靠性,为确定滚压力和槽深之间的关系提供了必要的指导依据.同时,为进一步研究螺旋槽管在滚压过程中的力学性能奠定了一定的理论基础. 相似文献
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24-200型柴油机系高速大马力柴油机。进气管长1952mm,内径180mm,壁厚7mm,有8个变截面支气管,要求气体流道圆滑过渡,内表面光滑。具体结构见图1。 相似文献
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介绍了 NB/T 47013.3-2015标准对锅炉、压力容器等设备管子和压力管道的环向对接焊接接头用对比试块的设计、制作要求,对不同设计方案进行了分析和比较,给出了壁厚不小于6 mm且曲率半径为80~250 mm的环向焊接接头超声检测用对比试块的曲率半径设计方案,解决了壁厚为4~6 mm且曲率半径在80 mm以上的承... 相似文献
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李永康 《稀有金属材料与工程》2021,50(2):519-524
为改善平面流铸冷却辊的换热特性,提高Fe-Si-B非晶薄带的横向厚度均匀性,建立了冷却辊轴向换热通道数值计算模型。在分析现有通道流动换热特性基础上,提出一种球面形换热通道设计方法。基于场协同理论,综合换热与流阻,对所提球面形通道进行优化,并进行实验验证。结果表明:通道内冷却水换热效率沿水流方向逐渐下降,与冷却辊换热主要发生在靠近冷却辊内壁位置,现有冷却辊宽度中部温度远大于两端,轴向温差明显;球面形通道可以加强冷却辊中部换热,降低外壁温度、热变形和轴向变形差,进而改善非晶薄带横向厚度均匀性;随着球面半径的减小,通道中部换热明显增强,但流阻随之急剧增大;综合流阻与换热特性,存在最优通道优化半径。 相似文献
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铝合金弹性预应力超声喷丸成形试验 总被引:2,自引:0,他引:2
超声喷丸作为一种新型的板料成形技术,具有易操作,能耗少及优良成形性能等优点,广泛应用于板料成形中。但自由状态下,超声喷丸成形也易发生球面变形,因而提出了弹性预应力超声喷丸成形方法,以2024-T351铝合金壁板为研究对象,分析预弯力矩大小、成形轨迹和壁板厚度对成形曲率半径及成形性能的影响。试验中通过控制壁板展向的弯曲曲率来实现弹性预弯。结果表明:预应力超声喷丸能够大幅度减小壁板展向的成形曲率半径,同时增大弦向成形曲率半径,且随着预弯曲率半径的减小,这种减小和增大的效应随之逐渐增大。此外,与自由状态相比,预应力超声喷丸能够产生幅度和深度更大的残余压应力场,且表面粗糙度并未随着预弯曲率的增大而增加。分析认为,弹性预应力超声波喷丸能够进一步提高受喷材料的成形曲率并在一定程度上减小球面变形趋势,对大变形大厚度的单曲率零件成形具有重要的意义。 相似文献
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By applying ultrasonic-MIG welding as research object, the behaviors of welding arc were analyzed with varied ultrasonic parameters in welding using arc images recorded by high-speed camera. The influences of the current by exciting ultrasonic and the height and shape of ultrasonic radiator on welding arc were studied. Results showed that when the current was 150 mA, ultrasonic showed most distinct compressive effect on arc. The compressive volumes of arc length at different heights were calculated by adjusting the height of ultrasonic radiator continuously from 10 mm to 35 mm, there were three maximum points. The compressive degrees of them reduced successively. By utilizing different shapes of ultrasonic radiator, it revealed that ultrasonic radiator with spherical crown surface showed better compressive effect in a larger welding standard scope. When radius of radiator increased, axial compressive volume of arc enlarged, while an increasing curvature radius led to more distinct radial compression of arc. 相似文献
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《中国焊接》2018,(3)
This paper presents a numerical simulation of deformation and residual stress in butt-weld joint for different shaped plates.Within the framework of numerical investigation,3 types of models and a double ellipsoidal heat source were implemented in finite element simulation. As for an effect of geometric shape,the weld-induced deformation and residual stress should be taken into account during designing the welded structure. And for U-shape plates,the effect of curvature radius on the mechanical properties was also obtained,which is a significant factor affecting its service life. The simulation results revealed that the plate processed into U-shape could reduce the deformation and residual stress near the weld. And the deformation and residual stress in U-shape plate with circular arc transition were further reduced. Furthermore,the effect of curvature radius on the mechanical properties of plates was not general considered as the bigger curvature radius the better mechanical properties. The results concluded that the geometric shape significantly affects the mechanical properties,which provides prediction for structural design. 相似文献