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71.
Both experimental and finite element model (FEM) results are presented for the dynamic strength behavior of windshield subjected
to bird impact. The experimental data taken from a series of high speed photographs are compared with the numerical results
predicted by using FEM in which the windshield was modeled entirely with solid elements and the bird body was approximately
simulated by an elastic-plastic material with failure element behavior. Effective plastic strain and element pressure were
adopted as the failure criteria and once the pressure or the effective plastic strain of an element reached the critical value,
the element would lose the tensile resistance capability completely. The deflection and stress distribution in the windshield
were obtained. It is shown that the result from the finite element analysis agrees with those from the full-scale bird impact
test.
The project supported by the National Natural Science Foundation of China (10272011) 相似文献
72.
STRUCTURAL DAMAGE MODEL OF UNSATURATED EXPANSIVE SOIL AND ITS APPLICATION IN MULTI-FIELD COUPLE ANALYSIS ON EXPANSIVE SOIL SLOPE 总被引:1,自引:0,他引:1
Focused on the sensitivity to climate change and the special mechanical characteristics of undisturbed expansive soil, an elastc-plastic damage constitutive model was proposed based on the mechanics of unsaturated soil and the mechanics of damage. Undisturbed expansive soil was considered as a compound of non-damaged part and damaged part. The behavior of the non-damaged part was described using non-linear constitutive model of unsaturated soil. The property of the damaged part was described using a damage evolution equation and two yield surfaces, i.e., loading yield (LY) and shear yield (SY). Furthermore, a consolidation model for unsaturated undisturbed expansive soil was established and a FEM program named UESEPDC was designed. Numerical analysis on solid-liquid-gas tri-phases and multi-field couple problem was conducted for four stages and fields of stress, displacement, pore water pressure, pore air pressure, water content, suction, and the damage region as well as plastic region in an expansive soil slope were obtained. 相似文献
73.
Gao Yuanwen 《Acta Mechanica Solida Sinica》2007,20(2):180-188
An analysis of buckling/snapping and bending behaviors of magneto-elastic-plastic interaction and coupling for cantilever rectangular soft ferromagnetic plates is presented.Based on the expression of magnetic force from the variational principle of ferromagnetic plates,the buckling and bending theory of thin plates,the Mises yield criterion and the increment theory for plastic deformation,we establish a numerical code to quantitatively simulate the behaviors of the nonlinearly multi-fields coupling problems by the finite element method.Along with the phenom- ena of buckling/snapping and bending,or the characteristic curve of deflection versus magnitude of applied magnetic fields being numerically displayed,the critical loads of buckling/snapping, and the influences of plastic deformation and the width of plate on these critical loads,the plastic regions expanding with the magnitude of applied magnetic field,as well as the evolvement of deflection configuration of the plate are numerically obtained in a case study. 相似文献
74.
建立了同时测定塑料食品包装材料中8种苯并三唑类紫外吸收剂(UV-P、UV-234、UV-320、UV-326、UV-327、UV-328、UV-329和UV-360)的高效液相色谱-二极管阵列检测法。样品经5 m L乙酸乙酯+二氯甲烷(V/V=4:1)在20℃超声提取10 min后,以甲醇、乙腈和水为流动相梯度洗脱,经Eclipse XDB-C_(18)柱分离,在340 nm处检测。UV-P和UV-360以及其他6种紫外线吸收剂分别在0.02~10,0.2~10和0.1~10 mg/L的质量浓度范围内呈良好的线性关系。8种紫外吸收剂的线性相关系数均大于0.9999;仪器的检出限(S/N=3)为0.0074~0.1250mg/L。3种不同添加水平下的样品加标平均回收率为93.7%~114.3%,相对标准偏差均不高于5.0%(n=6)。 相似文献
75.
76.
杜翠娟 《分析测试技术与仪器》2011,17(1):51-55
介绍了用ICP-AES法测定塑料中镉含量的不确定度的评定方法.分析了测量不确定度的主要来源,对测试不重复性、工作曲线非线性、标准溶液、样品质量、定容体积等5个不确定度分量进行分析计算,最后合成ICP-AES法测定塑料中镉含量的相对标准不确定度为1.709%,并计算求得扩展不确定度. 相似文献
77.
78.
79.
橡胶增韧塑料机理的探讨 总被引:1,自引:0,他引:1
本实验采用透射电镜及新的RuO_4染色方法,观察研究了PC/PBT,PC/MBS/PS共混体系和AAS共聚共混物的银纹结构形态。结果表明:不同聚合物体系银纹产生的数量,银纹的发展、终止及支化各不相同。这时研究塑料增韧机理很有意义。 相似文献
80.
柱层析色谱分离性能优良的新型塑料脱模剂,纯化后得一主要未知组分。用元素分析、红外光谱、核磁共振氢谱研究其结构特征,对其盐酸酸化前后红外光谱吸收峰及核磁带进行了归属分析并确定结构。结果表明,该组分为一表面活性剂N,N-二羟乙基十二烷基胺。这为新型脱模剂的产品开发提供了依据。 相似文献