It is well known that additional stretching of the material in the unsupported wall area may prevent wrinkling , and this can be achieved in practice by increasing the blank - holder force ; but the application of excessive tensile stresses leads to failure by tearing 我们知道在不被支撑的拉伸壁区域中材料的外力拉伸可以防止起皱，这可以在实践中通过增加压边力而实现，但是运用过大的拉伸力会引起破裂失效。
This article performed an application of such means as modern test technology , computer processing system , serial ports communication and electrohydraulic proportional control technology to reform the sheetmetal combined testing machine , so that the stretching force , clamping force and the stretching length can be tested and controlled by the computer system , which greatly improved the stability and testing precision of the testing machine 摘要通过应用现代测量、微处理、串口通信、电液比例控制等技术，对自行研制的钣金综合试验机进行了改造，实现了对拉伸力、夹紧压力和拉伸长度的计算机数据采集和控制，大大提高了原系统稳定性和测试精度。
Analyzing the effects towards residual stress from different rolling loadcase , the value of cold rolling residual stress caused by different compress was gotten ; analyzing parameters stretching toward different rolling loadcase board , the effect of the residual stress elimination influenced by stretching force and stretching deformation was figured out 通过分析不同轧制工况对残馀应力分布的影响，得到不同压缩量对轧制残馀应力的影响； ?对不同轧制工况后的板材进行参数拉伸，得到拉伸力大小、拉伸变形量大小对残馀应力消除效果的影响值。
Three dimensional braiding preform reinforced resin composite is a new type of advanced composites and used in aircraft and space , transportation , construction , military project , medical treatment and physical education etc . 3 - d braiding composites will subject to long - term tensile force during applied process , which is a long - time creep process 树脂基三维编织复合材料是一种先进的复合材料，它已经应用于航空、航天、交通、建筑、军工、医疗、体育等领域。在应用过程中，三维编织复合材料会受到长期拉伸力的作用，这决定了它的使用过程是一个长期的过程，因此蠕变性能成为表征其力学性能的一个非常重要的指标。
