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为了解决船舶横位置对接焊缝中存在的焊接效率低、质量可靠性差等问题,开展了针对船舶对接焊缝的气电横焊技术研究。通过对水冷铜滑块、陶瓷衬垫等关键条件的设计优化,将气电焊技术扩展至船舶建造横位置对接焊缝的焊接。随后对坡口形式、焊枪位置、摆动幅度等关键焊接工艺参数进行了合理的设计,结合船舶结构特点及工艺覆盖的要求,进行了3组不同板厚的横位置对接焊试验,测量了不同板厚的抗拉强度、硬度及冲击吸收能量,以验证工艺的可行性。结果表明,由于焊缝表面采用水冷铜滑块强制成形及焊缝根部采用陶瓷衬垫成形的影响,得到的焊缝成形美观,避免了焊后打磨处理,大大减轻了劳动强度;各个板厚的抗拉强度、硬度及冲击吸收能量等试验数据均满足船级社规范要求,并具有较大的工艺裕量;热输入最高可达93 kJ/cm,焊接效率相较于常规FCAW横焊提高了8倍左右。
创新点: (1)对陶瓷衬垫以及水冷铜滑块设计优化,有效解决了船舶横位置对接焊缝中根部焊缝的熔合问题。(2)将气电横焊技术用于船舶横位置对接焊缝的焊接,提高了横位置对接焊缝的焊接效率。 相似文献
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为了实现船舶焊接件数字模型中焊缝特征参数的精确提取,进而完成机器人数据库系统中焊接工艺的自适应快速匹配和快速选择,提出了基于空间位置和轮廓线距离的船舶焊缝特征参数提取算法.首先基于海伦公式识别待判定面来确定接头空间位置关系,并结合最小轮廓线距离完成焊缝特征识别;然后基于轮廓线总条数和最小轮廓线距离的两端点,识别出焊缝坡口处特征点及线;最后基于三类焊接接头所建的数学模型提取出与焊接工艺相关的焊缝特征参数.测试结果表明,文中焊缝特征参数提取算法能准确识别4类接头形式和10种坡口类型,以及准确提取焊缝间隙、坡口夹角和焊接件板厚等参数,具有焊缝特征识别广且信息提取齐全的优点.与其他相关识别算法相比,文中算法的识别率达到100%,而识别效率提升了16.06%,从而进一步验证了算法的有效性. 相似文献
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This paper presents generalized CAPP (G-CAPP) method which deals with macro process planning for multiobjective in the planning stage of production line of accuracy welding (PLAW) based on the features of accuracy welding production ( AWP ). G-CAPP offers foundations for prototype design and general equipment sorting, production capacity predication and production analysis by means of simulation and optimization. A synthetic hierarchy evaluation (SHE) model for G-CAPP established according to the planning objective is utilized to estimate the alternate processing plans by using membership function and analytic hierarchy process (AHP) of operational theory. The assembly welding line of hydraulic torque converter (HTC) is as an example of typical A WP to explicate G-CAPP and synthetic evaluating strategy of PLAW. The feasible and rational process configuration strategies of HTC assembly welding line are pointed oat under different planning objective. 相似文献
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飞机液压管路膨胀环能够很大程度上吸收外载荷产生的多余应力,但是会增加管路系统质量,进而降低功重比。以管路静力学、动力学及质量为优化目标,推导与膨胀环折弯角度、弯曲半径、跨度和高度4个参数相关的各目标函数。不同函数的量纲通过层次分析法进行统一,使多目标优化问题转向单目标优化问题。其中,通过调整目标函数的权重系数来体现多个目标的不同重要程度,再结合遗传算法求解得到膨胀环最优设计参数,最后对膨胀环动力学数学模型进行了实验验证。结果表明:膨胀环动力学数学模型准确性较高,引入的层次分析遗传算法能权衡管路综合特性,得到膨胀环的合理结构参数。 相似文献
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Alexander Govik Larsgunnar Nilsson Ramin Moshfegh 《Journal of Materials Processing Technology》2012,212(7):1453-1462
An increasing number of components in automotive structures are today made from advanced high strength steel (AHSS). Since AHSS demonstrates more severe springback behaviour than ordinary mild steels, it requires more efforts to meet the design specification of the stamped parts. Consequently, the physical fine tuning of the die design and the stamping process can be time consuming. The trial-and-error development process may be shortened by replacing most of the physical try-outs with finite element (FE) simulations of the forming process, including the springback behaviour. Still it can be hard to identify when a stamped part will lead to an acceptable assembly with respect to the geometry and the residual stress state. In part since the assembling process itself will distort the components. To resolve this matter it is here proposed to extend the FE-simulation of the stamping process, to also include the first level sub-assembly stage. In this study a methodology of sequentially simulating each step in the manufacturing process of an assembly is proposed. Each step of the proposed methodology is described, and a validation of the prediction capabilities is performed by comparing with a physically manufactured assembly. The assembly is composed of three sheet metal components made from DP600 steel which are joined by spot welding. The components are designed to exhibit severe springback behaviour in order to put both the forming and subsequent assembling simulations to the test. The work presented here demonstrates that by using virtual prototyping it is possible to predict the final shape of an assembled structure. 相似文献
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QTT (Qitai radio telescope)天线轨道每段尺寸4 000 mm × 600 mm × 200 mm,进行多层多道焊拼接时,坡口与熔敷金属量大,角变形大. 为了预测与控制变形,通过轨道缩比模型的试验与有限元分析,验证了热弹塑性耦合模型的合理性,并在有限元模型中考虑了重力的影响. 同时为解决大型QTT天线轨道结构多层多道焊模拟计算量大的问题,增加了重力弯矩影响,对多层多道焊角变形预测公式进行了修正. 结果表明,对于大型QTT天线轨道结构,重力影响因素不可忽略,且添加重力条件提高了模型角变形预测精度,为新一代大型QTT天线轨道实际装焊提供了理论指导. 相似文献
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大型三维复杂构件是船舶、海洋装备、集装箱等的重要组成部分,其焊缝种类较多、空间分布复杂,部分焊缝存在协同同步弧焊焊接、焊接方向等特殊焊接工艺约束,现有协同焊接规划方法难适用于这类复杂场景。提出全局与局部相结合的双机器人协同焊接路径规划多阶段寻优方法;建立复杂构件三维空间焊缝模型以及双焊接机器人协同模型;根据协同同步焊焊缝的数量将构件划分出相应数量的分块,通过蚁群算法求解每一焊接分块的局部路径规划近似最优解;通过遗传粒子群算法进行多分块间的全局路径规划。仿真结果表明:通过分块划分多阶段寻优的方法可以有效地解决特殊焊接工艺约束下的大型三维复杂构件双机器人同步焊接路径规划问题。 相似文献
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针对汽车车身焊装自动化生产线各类夹具快速设计的需要,提出了一种基于基元模型的车身焊接夹具分层实例推理设计方法. 在对各类焊接夹具设计特征分析的基础上,给出了由形状特征、位置特征和装配特征等3个子特征所描述的焊装特征模型. 建立了一种基于基元模型的焊接夹具设计知识的表达与存储方法,形成了基于知识重用的焊装工位信息模型. 从焊装特征的角度,分3个阶段对焊装工位信息的相似度进行计算,通过映射获取最相似的夹具实例. 以某车型内蒙皮加强板分总成工位为研究对象进行了应用,验证了文中所提方法的高效性. 相似文献
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Welding deformation and residual stress have negative influence on assembly accuracy and service performance. Thermal elastic plastic (TEP) and inherent strain finite element analysis (FEA) methods were used to study this challenge. Basic principle of these two methods was first introduced. The influence of welding process, constraints, solid phase transformation and multi-pass welding on deformation and residual stress was discussed, and computation accuracy and efficiency were summarised. Loading method of inherent strain in inherent strain FEA was analysed, interface element was introduced to simulate effects of the gap on deformation in assembly welding especially for large structures. The future work, including accurately multiscale TEP model, efficiently transient prediction method of large structures, and flexible evaluation software, was planned. 相似文献