共查询到19条相似文献,搜索用时 912 毫秒
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对大型TC4钛合金变壁厚半球壳体的超塑胀形工艺进行了研究。采用数值模拟手段先后分析了单向胀形和正反胀形后半球毛坯的壁厚分布规律,指出了正反胀形工艺在壁厚分布上的优势,并给出了反胀模具型面曲线优化的关键参数及其对成形壁厚分布的影响规律。用优化后的模拟数据结果指导实际实验参数设计,在理论分析基础上进行了实验验证。结果表明,数值模拟数据较好地预测了超塑成形后的半球壁厚分布,利用优化后的正反胀模具实现了半球实验件的壁厚按需分配。成形后材料强度略有下降,延伸率得到提升。正反胀形方法能够明显提高钛合金板材的材料利用率和后续毛坯的车加工效率,降低制造成本。 相似文献
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为了提高锥形件超塑成形效率,提出了叠层超塑成形工艺及高温进出炉成形方案,并采用正反向超塑成形方法以提高壁厚分布均匀性。通过对超塑成形过程自由胀形阶段与贴模成形阶段进行的力学解析,得到了最佳等效应变速率条件下的气压加载曲线。以此为基础,对单层正向成形、单层正反向成形及双层正反向成形进行了920℃超塑成形实验研究。结果表明,正反向成形可显著改善锥形件壁厚均匀性。在双层正反向成形条件下,锥形件最大截面圆度为0.05 mm,最小壁厚为1.01 mm,型面尺寸及壁厚分布均满足使用要求,下层零件的壁厚均匀性较差。叠层超塑成形工艺及900℃装出炉方案可行有效,可使锥形件超塑成形效率提高1倍以上。 相似文献
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壁厚分布对薄壁构件的结构性能有重要影响。本文研究超塑成形件壁厚分布的预测技术,实现了超塑成形过程的有限元数值模拟的成形件厚度分布曲线的自动预测,以半球壳和矩形盒成形为例,为自由胀形和约束胀表两种情形形件厚度变化进行了分析,预测结果与实验数据吻合。 相似文献
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镁合金板材正反向快速气压胀形实验 总被引:1,自引:0,他引:1
采用两种不同轮廓的反向预成形模具进行高应变速率气压胀形实验,结果表明,内外凹圆弧预成形模的成形效果好于半圆弧预成形模,反向胀形的时间可控制在10s,表面和微观组织均无明显缺陷。利用上述预成形模进行半球件正反向气压自由胀形实验,研究正反向胀形的效果,正反向胀形可以显著提高AZ31B镁合金板料的成形能力,使胀形件高径比从0.344提高到0.522,并使壁厚均匀度从19.4%提高到半圆弧预成形模具的32.3%,内外凹圆弧预成形模具的45.5%。在400℃温度下胀形300s,可以成形出高径比为0.522的完好半球件。 相似文献
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运用有限元分析软件Dynaform对厚板小圆角端盖进行多工序成形过程模拟。通过对一组首次整形工艺参数进行有限元模拟,分析了首次整形的凸模和凹模圆角对零件多工序成形后壁厚、成形极限图的影响。从中找到一组最优化的冲压工艺参数,并成功完成了厚板小圆角端盖模具的设计。 相似文献
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George Luckey Jr. Peter Friedman Klaus Weinmann 《Journal of Materials Processing Technology》2009,209(4):2152-2160
The conventional superplastic forming (SPF) of complex and deep geometries can result in excessive thinning and necking. To address these issues, a two-stage SPF process has been developed and demonstrated in forming trials using a superplastic aluminum sheet alloy. Within a single die, gas pressure is used to form the blank into a preform die cavity prior to the pressure being reversed to form the sheet into the final component cavity. The preforming of the blank creates length of line, while preserving metal thickness in certain regions to improve the thickness profile of the final part. In this work, a preform has been designed to improve the forming of a complex component by providing a superior thickness profile as compared to a conventional single stage forming cycle. Finite element analysis was used to guide the design of the preform cavity since the preforming surface was not intuitive and could cause wrinkling in the final part. 相似文献
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根据正交试验原理,应用板料成形软件Pamstamp 2G对不同压边力、模具与板料间摩擦因数、凸、凹模间隙和板料初始尺寸进行数值模拟,将数值模拟的板料厚度同实际成形件厚度进行比较,得出上述各因素对前翼子板成形结果的影响,并预测了前翼子板优化的成形工艺条件。 相似文献
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Over the past thirty years Superform has been a pioneer in the SPF arena, having developed a keen understanding of the process
and a range of unique forming techniques to meet varying market needs. Superform’s high-profile list of customers includes
Boeing, Airbus, Aston Martin, Ford, and Rolls Royce. One of the more recent additions to Superform’s technical know-how is
finite element modeling and simulation. Finite element modeling is a powerful numerical technique which when applied to SPF
provides a host of benefits including accurate prediction of strain levels in a part, presence of wrinkles and predicting
pressure cycles optimized for time and part thickness. This paper outlines a brief history of finite element modeling applied
to SPF and then reviews some of the modeling tools and techniques that Superform have applied and continue to do so to successfully
superplastically form complex-shaped parts. The advantages of employing modeling at the design stage are discussed and illustrated
with real-world examples. 相似文献
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数值模拟技术在汽车覆盖件成形中的应用 总被引:31,自引:18,他引:13
金属薄板成形的数值模拟技术在汽车覆盖件生产及其模具设计制造中起着十分重要的作用。数值模拟技术的广泛应用可以帮助模具设计人员显著地减少模具开发时间、试模周期和费用。为此,详细介绍了应用Dynaform软件模拟覆盖件成形过程的一般步骤,并以某汽车覆盖件的拉深为例,对其成形过程进行了数值仿真。通过对模具零件的运动、板料的成形,以及板料厚度的变化,应力应变分布,成形极限预测等结果的分析,进一步弄清了板料形状,压料筋布置以及压边力大小等工艺参数对汽车覆盖件质量的影响。在案例分析的基础上,针对覆盖件坯料拉深过程中可能出现的起皱现象,给出了相应的拉深工艺优化和模具方案优化。 相似文献