Investigation of Residual Stresses in Polystyrene Products by Ultrasonic Technique

الموضوعات

علوم تطبيقية وتكنولوجية

الملخص

Residual stresses are built up due to various processing operations and affect significantly on the materials performance. It is important to develop accurate and reliable methods for analysis of residual stresses in engineering components that causes catastrophic fracture without previous warning. Polymers are poor in the resistance to crack extension, so the residual stresses are influencing inevitably on the performance of polymeric products. The development of nondestructive techniques (NDT) is very important from technical and economical point of view. The ultrasonic technology is more extensively applied in the assessment of residual stresses in metals. In this work, the ultrasonic pulse-echo technique was applied on the first time in measuring residual stresses for polystyrene products. According to the difference in morphology between polymeric components, through thickness residual stresses were determined twice in this work. Through thickness residual stresses in terms of acoustoelastic constant and through depending on the determined previously acoustoelastic constant for polystyrene sheets. The residual stresses were evaluated due to cooling from temperatures (180, 200)by air and water under various applied pressures (0, 45.714, 76.19, 106.667, 152.381)MPa. The ultrasonic velocity of reference (annealed) specimen (2260) m/s was approved in the evaluation of residual stresses due to ultrasonic test. The air and water cooling from (180, 200)were corresponded with increasing in ultrasonic velocity while tensile residual stresses were related with decreasing in ultrasonic velocity for evaluated residual stresses in terms of acoustoelastic constant. SPSS software through (p-value)were showed that air and water cooling from(180, 200)resulted tensile residual stress without zero pressure. The optimum pressures against residual stresses from (HABCFFNN) were obtained under (106.667, 76.19)MPa pressures while the optimal through thickness residual stresses due to water cooling from (180, 200)were (-70.003, IV10.579)MPa. The best temperature of preparing polystyrene specimens was 200because the high percent of beneficial compressive residual stresses that increase fatigue and creep strength. The evaluated through thickness residual stresses were resulted from (thermal stresses due to cooling type, over load applied pressures, restraining of polymeric sheets inside metal molds). The range of ultrasonic velocity produced from pulse-echo test were (2000-2500) m/s due to air and water cooling from (180, 200). From SPSS, the significant pressure on residual stresses due to water cooling from (200)was 152.714.

روابط وملفات

التعريف والنوع

رقم الوثيقة

09583d41-ac0d-4103-a66d-9e806d627762

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل دكتوراة

نوع الملف

pdf text

أسماء الملفات

993555_1.pdf

بيانات النشر

ترجمة العنوان

التحقق من الاجهادات المتبقية في منتج من البولي ستيرين باستخدام تقنية الموجات فوق الصوتية

ألقاب المؤلفين

[{"name_ar":"علي عبد الامير الزبيدي","title_ar":"اشراف","title_en":"Supervision"},{"name_ar":"لينا فاضل كاظم","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"هناء جواد كاظم","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

English

المصدر والدورية

اسم المصدر

Investigation of Residual Stresses in Polystyrene Products by Ultrasonic Technique

المحتوى والصفحات

عدد الصفحات

0

كلمات الباحثين

Residual stresses, filtration, structural seals, styrene structures, thermal stresses, cooling, engineering measurements, SPSS, artificial neurons

إشراف وإعداد

الإشراف

علي عبد الامير الزبيدي, هناء جواد كاظم

الإعداد

لينا فاضل كاظم

الاقتباسات الببليوغرافية