Maximum circumferential stress criterion of brittle fracture for v - notch 型切口脆性斷裂的最大周向應(yīng)力準(zhǔn)則
Standard test method for shear properties of composite materials by v - notched rail shear method 用v型切口梁剪切試驗(yàn)測定復(fù)合材料剪切特性的標(biāo)準(zhǔn)試驗(yàn)方法
The directions of crack orientation and the critical loads predicted by the above criterions coincide with the experiment results 運(yùn)用上述各準(zhǔn)則對這些v型切口模型的裂紋起裂方向和臨界載荷進(jìn)行了理論預(yù)測,預(yù)測結(jié)果與實(shí)驗(yàn)結(jié)果基本吻合。
In order to verify these criterions , tensile experiments are carried out for many kinds of samples made out of plexiglas with a planar v - notch under mixed - mode of i and ii 為了檢驗(yàn)上述脆性斷裂準(zhǔn)則,用脆性材料pmma加工成多種型、 -復(fù)合型v型切口試樣,進(jìn)行了拉伸破壞實(shí)驗(yàn)。
Based on the basic equations of the elasticity plane problem , displacement fields and singular stress fields near the v - notch tip under mixed - mode of i and ii are obtained for homogeneous materials by a new definition of the stress intensity factors 基于彈性力學(xué)平面問題的基本方程,通過重新定義應(yīng)力強(qiáng)度因子,推導(dǎo)了均質(zhì)材料-復(fù)合型v型切口尖端附近的位移場和奇異應(yīng)力場。
Based on the basic equations of the elasticity plane problem and the two airy stress functions in the thesis , stress singularity eigenequations and displacement fields as well as singular stress fields near the v - notch tip and the crack tip for homogeneous materials are obtained 本文基于彈性力學(xué)平面問題的基本方程,引入兩個(gè)airy應(yīng)力函數(shù),推導(dǎo)了均質(zhì)材料型切口尖端和裂紋尖端的應(yīng)力奇異性特征方程及其附近的奇異應(yīng)力場和位移場。
Based on the theory of fracture mechanics , the relation between the critical stress intensity factors for v - notch kc and the plane strain crack toughness k10c and the brittle fracture criterion of the maximum circumferential stress for single and double stress singularity with the v - notch problems are proposed . experiments were carried out using two kinds of v - notched specimens made out of plexiglas to verify this brittle fracture criterion 本文基于斷裂力學(xué)原理,推導(dǎo)出了型切口的臨界應(yīng)力強(qiáng)度因子k _ c與材料的平面應(yīng)變斷裂韌度k _ ( 10c )之間的關(guān)系,給出了平面單奇異性和雙奇異性型切口問題的最大周向應(yīng)力脆性斷裂準(zhǔn)則,并用有機(jī)玻璃板材加工了兩種型切口試樣,進(jìn)行了實(shí)驗(yàn)驗(yàn)證。
According to the strain energy density factor criterion under mixed - mode of i and ii , the distortional strain energy density factor criterion and dilatational strain energy density factor criterion are given . the twin shear stress criterion is applied to the v - notch problem under mixed - mode of i and ii 基于-復(fù)合型v型切口的應(yīng)變能密度因子準(zhǔn)則,提出了形狀改變能密度因子準(zhǔn)則和體積改變能密度因子準(zhǔn)則,將雙剪應(yīng)力準(zhǔn)則有效地應(yīng)用到-復(fù)合型v型切口問題。
By utilizing the above methods and the results of the finite element program named msc / nastran , the paper carries through specific calculations corresponding to the single stress singularity and the double stress singularity issues , which consist of the cracks for mode i , mode ii , the mixed mode crack of mode i and ii and many v - notched problems 利用上述數(shù)值方法和有限元程序msc nastran的數(shù)值分析結(jié)果,對型、型、與復(fù)合型平面裂紋以及多種型切口問題進(jìn)行了具體計(jì)算。計(jì)算結(jié)果表明,本文所提出的數(shù)值方法具有簡單、通用和精度高的特點(diǎn),便于實(shí)際工程應(yīng)用。