共查询到20条相似文献,搜索用时 265 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
小径管座角焊缝内部缺陷检测是无损检测的难点。根据急冷换热器中的管座角焊缝规格制作了模拟试块,并加工了人工缺陷,分别用相控阵超声检测、常规超声检测和射线检测这三种方法对模拟试块的缺陷尺寸进行评定,以选择恰当的检测方法。结果表明,对缺陷尺寸还原程度最好的是射线检测,其次是相控阵超声检测。但是由于小径管座的结构原因,在制造过程中无法进行射线检测,相控阵超声检测是小径管座角焊缝缺陷检测的最佳选择。 相似文献
9.
10.
针对大壁厚压力容器接管焊缝多为窄间隙对接焊接头,超声检测中存在扫查路径复杂、定量定性精度差和检出率相对较低等难点,引入有限元模拟仿真技术。通过建立工件3D模型和不同类型的缺陷,模拟各缺陷在压力容器筒体外壁和接管内壁相控阵超声检测时的响应情况,优化相控阵超声探头、楔块设计和探头运动轨迹,最终实现检测工艺的理论设计。在带有自然缺陷的模拟试块上,验证检测工艺的准确性和可靠性。对比有限元模拟仿真和在模拟试块上的实际检测情况表明,经过仿真设计过的相控阵超声检测工艺可有效提高接管窄间隙焊缝中缺陷的检出率和检测精度。 相似文献
11.
介绍了西气东输二线自动超声波探伤对比试样人工缺陷的种类、位置及作用,并分析了对比试样对探伤系统探头数量的要求,两组检测纵向缺陷探头即可完成内外表面纵向刻槽的校验。通过数学方法计算了超声波探头的有效声束宽度,结果表明当钢管壁厚为26.4,27.5和33.0mm时,即使两组探头可完成对比试样的校验,但探伤系统无法覆盖整个壁厚范围。此时有必要对试样进行完善,建议可在对比试样中增加位于焊缝壁厚中心沿长度方向的西3.2mm的水平钻孔,以准确对探伤系统在壁厚方向上的检测能力进行检验。 相似文献
12.
研究了应用超声红外技术检测复合材料试件冲击损伤缺陷。针对红外图像对比度差、缺陷轮廓模糊等特点,采用具有非高斯核函数的LBF模型进行了缺陷的边缘检测,利用缺陷边缘实现了缺陷的定量分析。从试验结果可以看出,LBF模型相对于其它常用的边缘检测方法,能够很好地检测低对比度红外图像的目标边缘,为复合材料缺陷的定量分析奠定了基础。从缺陷的长度和宽度定量计算精度可见,超声红外检测方法对于复合材料的缺陷是一种有效的检测手段,为复合材料的研制提供了强有力的技术支持。 相似文献
13.
14.
15.
A.M. Visco L. Calabrese P. Cianciafara L. Bonaccorsi E. Proverbio 《Journal of Materials Engineering and Performance》2007,16(6):792-799
Polyester resin based composite materials are widely used in the manufacture of fiberglass boats. Production time of fiberglass
laminate components could be strongly reduced by using an intense energy source as well as microwaves. In this work a polyester
resin was used with 2% by weight of catalyst and reinforced with chopped or woven glass fabric. Pure resin and composite samples
were cured by microwaves exposition for different radiation times. A three point bending test was performed on all the cured
samples by using an universal testing machine and the resulting fracture surfaces were observed by means of scanning electron
microscopy (SEM). The results of mechanical and microscopy analyses evidenced that microwave activation lowers curing time
of the composite while good mechanical properties were retained. Microwaves exposition time is crucial for mechanical performance
of the composite. It was evidenced that short exposition times suffice for resin activation while long exposure times cause
fast cross linking and premature matrix fracture. Furthermore high-radiation times induce bubbles growth or defects nucleation
within the sample, decreasing composite performance. On the basis of such results microwave curing activation of polyester
resin based composites could be proposed as a valid alternative method for faster processing of laminated materials employed
for large-scale applications. 相似文献
16.
17.
18.
19.
《Acta Materialia》2004,52(9):2691-2700
The present study describes the fatigue crack growth behavior of [0/90]2s and [90/0]2s laminates of Ti–6Al–4V/SCS-6 composite containing either part-through thickness or through thickness defects under a constant load range at room temperature in air. This study also compares the effect of composite architecture on the fatigue crack growth resistance of these laminates. Acoustic emission was used to detect the number and the location of in situ fiber failures. It was found that the specimens containing part-through thickness defects showed lower crack arrest/catastrophic failure (CA/CF) transitions compared to the specimens where cracks were grown from through thickness defects. Additionally, the higher CA/CF transition of [90/0]2s laminate compared to [0/90]2s laminate irrespective of defect geometry could be attributed to the composite architecture or lay up sequences in these laminates. 相似文献
20.
复合材料计算机层析照相检测及应用 总被引:3,自引:0,他引:3
介绍CT检测复合材料的原理和方法。利用研制的软件对断层扫描的图像数据进行三维重建、分析和测量。实验表明,CT检测复合材料内部缺陷具有很好的分辨力,三维重建能够很好地显示密度的空间分布情况,CT检测是目前最精确、有效的无损评价方法之一。 相似文献