【摘要】 研究温度和应力对7050铝合金预拉伸板中的超声纵波、偏振横波和临界折射纵波传播速度的影响,并分析不同频率临界折射纵波在梯度应力场中的传播规律。结果表明:温度对声速的影响大于声弹效应的影响;单轴拉伸时,沿轴向传播的临界折射纵波、平行轴向偏振的横波的速度降低,垂直应力方向偏振横波的速度升高,垂直轴向传播的纵波速度变化不大;临界折射纵波的频率越高,其所反映的应力越接近表面;声弹性法测得的应力是声传播路径上各点应力在超声波造成的质点振动方向上分量的综合反映。更多还原

【Abstract】 Effect of temperature and stress on velocity of ultrasonic longitudinal wave,polarized shear wave,longitudinal critically refracted(LCR)wave in pre-stretched 7050 aluminum alloy plate was investigated.Regularity of LCR wave with different frequency propagating in gradient stress field was analyzed.The results show that effect of temperature on velocity of ultrasound is more than that of acousto-elastic effect.When specimen is axially tensioned,velocity of LCR wave propagating along axial and shear wave polarizing parallel to axial decreases,velocity of shear wave polarizing perpendicular to axial increases,and velocity of longitudinal wave propagating perpendicular to axial hardly changes.LCR wave with higher frequency indicates stress nearer to surface.Tested stress by acoustic elasticity represents mean stress components in direction of particle vibration induced by ultrasonic.更多还原