Analysis on membrane wrinkling using stress extremum method

A stress extremum method is developed based on Von Karman equations for analysis of membrane wrinkles in this paper.A mechanical model is also established for analyzing shear membrane wrinkles.Expressi...     

浅锥形刻度盘成形工艺

介绍了浅锥形件正反拉伸成形工艺特点及模具结构设计要点 ,分析刻度盘在成形过程中产生的缺陷 ,并提出了防止措施     

多点压机成形与多道次多点模具成形的数值模拟研究

变形路径对于板材的成形质量有着重要的影响。多点压机成形和多道次多点模具成形充分利用多点成形的柔性特点,实现了对板材变形路径的控制。文章通过有限元数值模拟研究了这两种成形方式各自的特点和规律,并进行了比较。结果表明,多点压机成形和多道次多点模具成形,都能够优化板材变形路径,使变形均匀,有效地抑制起皱,提高板材变形能力。在同样条件下,多点压机方式好于多道次成形,但当多道次成形道次逐渐增多时,成形质量接近于多点压机成形。多点压机成形是理想化的成形方式,但设备造价昂贵,多道次多点模具成形可以近似实现多点压机成形效果。     

管材内高压胀形的实验研究与数值模拟

介绍了管材无模轴压胀形的实验,研究表明,适度的褶皱有助于提高成形极限。有限元数值模拟显示,随着内压—轴压匹配模式的改变,内压增长率对褶皱的演化表现出不同的影响效果。针对管坯—模具间摩擦对T型管复合胀形成形性的影响,分别从实验和有限元数值模拟两方面进行了研究。     

EFFECT OF ELASTOMER ON WRINKLE RECOVERY OF SILK AND SILK/WOOL BLEND FABRICS

An investigation is described in which various polyfunctional elastomers( cationic methylaminopolysiloxane,nonic concentrated glyoxal resin and anionicpolyurethane etc. ) were applied on silk,wool and silk/ wool blend fabrics forimprovement wrinkle recovery.A study on this paper describes wrinkle recovery oftreated fabrics by the thermobench method,and ascertains reason which elastomerimproves wrinkle recovery of silk and silk/ wool blend fabrics according as results ofthe DSC,the SEM and the acid or alkali resistance.     

基于肌肉模型的人脸皮肤皱纹模拟

在传统肌肉模型所实现的人脸表情动画基础上,通过对三维人脸网格模型进行细分并基于肌肉模型进行人脸皱纹模拟,从而提高了表情动画的逼真度和真实感。     

Analysis of effect of pressure on surface accuracy for inflatable antenna

Pressure is one of the important measures to control the surface accuracy of the reflector of inflatable antenna. Experiments and numerical analysis were carried out to highlight the effect of pressure on accuracy. The rapid, contactless and low-cost digital photogrammetry system （DIES） was employed to investigate the effect according to its lightweight and flexible characteristics. Measurement data show that the best pressure and the best area in this pressure can be obtained. Numerical analysis was conducted to check the measurement result. It is indicated that there is a little difference between them attributed to wrinkle. Results of analysis and experiments show that surface accuracy of the reflector can be adjusted by controlling pressure.     

Numerical analysis and experimental studies of membrane wrinkles

Wrinkling patterns and the rules of wrinkling formation and expansion were analyzed in this paper. Direct disturbing method,a numerical method for membrane wrinkling analysis,was established based on finite element programme. The experimental results using photogrammetric procedure were compared with numerical analysis results. It is shown that the reasonable wrinkling deformation can be obtained by rational mesh density and timely removes the initial flaw during analysis. Wrinkles firstly appear on the left and right sides then extend to the membrane center,and the wrinkling amplitude increases with shear displacement. Results from both of the experiments and numerical analysis have a good agreement,which verifies the rationality of the numerical analysis method.     

改性超支化聚酰胺HBPAMAM-EP的制备及复合物在棉织物上的应用

采用环氧氯丙烷对端氨基超支化聚酰胺(HBPAMAM)进行端基改性,制得端环氧基超支化聚酰胺(HBPAMAM-EP),并将其与ZnO复合应用于棉织物整理,制备成具有多功能性的棉织物。结果表明,当HBPAMAM与环氧氯丙烷比例为1∶28,开环反应温度55℃,闭环反应温度30℃,催化剂50%KOH 4 mL时制得的产物环氧值和产率都较高。经HBPAMAM-EP-ZnO复合整理的棉织物抗紫外性能表现优良(紫外线防护系数UPF为50+);改性棉织物在紫外灯照射下光催化降解亚甲基蓝MB,3 h降解率为99.49%;经HBPAMAM-EP和HBPAMAM-EP-ZnO整理的棉织物折皱回复角接近270°(未处理棉织物折皱回复角为179°),抗折皱性能明显增强。同时,经耐水洗测试表明经HBPAMAM-EP-ZnO整理的棉织物在洗涤30次,依旧能具有较好的抗紫外(UPF>50)、抗皱性能(折皱回复角210°左右),光催化性能(洗涤50次后降解率75%)。