Mechanics and dynamics of milling thin-walled structures
Başlık çevirisi mevcut değil.
- Tez No: 400702
- Danışmanlar: DR. YUSUF ALTINTAŞ
- Tez Türü: Doktora
- Konular: Makine Mühendisliği, Mechanical Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 1994
- Dil: İngilizce
- Üniversite: The Unıversıty Of Brıtısh Columbıa
- Enstitü: Yurtdışı Enstitü
- Ana Bilim Dalı: Makine Mühendisliği Ana Bilim Dalı
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: Belirtilmemiş.
Özet
Özet yok.
Özet (Çeviri)
Peripheral milling of flexible components is a commonly used operation in the aerospace mdustrj'. Aircraft wings, fuselage sections, jet engine compressors, turbine blades and a variety of mechanical components have flexible webs which must be finish machined using long slender end mills. Peripheral milling of very flexible plate structures made of titanium alloys is one of the most complex operations in the aerospace industry and it is investigated in this thesis. Flexible plates and cutters deflect statically and dynamically due to periodically varying milling forces and self excited chatter vibrations. Static deflections of the plate and cutter cause dimensional form errors, whereas forced and chatter vibrations result in poor surface quality and chipping of the cutting edges. In this thesis, a comprehensive model of the peripheral milling of very flexible cantilever plates is presented. The plate and cutter structures are modeled by 8 node finite elements and an elastic beam, respectively. The cutting forces are shown to be very dependent on the magnitude of the plate and cutter deformations which are irregular along the helical end mill-plate contact. The interaction between the milling process and cutter-plate structures is modeled, and the milling forces, structural deformations and dimensional form errors left on the finish surface are accurately predicted by the simulation system developed in this study. A strategy, which constrains the maximum dimensional form errors caused by static deformations of plate and cutter by scheduling the feed along the tool path, is developed. The variation of the plate thickness due to machining and the partial disengagement of the plate and cutter due to excessive static deflections are considered in the model. The simulation system is proven in numerous peripheral milling experiments with both rigid blocks and very flexible cantilevered plates.The self excited vibrations observed during peripheral milling of very flexible structures with multi-degree of freedom dynamics is investigated. A novel analytical model of milling stability is developed. The stability model requires structural transfer functions of plate and cutter, milling force coefficients and helical end mill geometry. Chatter vibration free cutting speeds, axial and radial depths of cut, i.e. stability lobes, are predicted analytically without resorting to computationally expensive time domain simulations. The analytical chatter stability model is verified in various peripheral milling experiments, including the machining of plates. The cutting force and chatter stability models developed in this thesis can be used to improve the productivity of peripheral milling of thin webs by enabling simulation and process planning prior to production.
Benzer Tezler
- Modeling milling of thin-walled parts considering dynamic structure-process interactions
İnce cidarlı parçaların frezelenmesi işleminin dinamik yapı-süreç etkileşimlerinin hesaba katılarak modellenmesi
SALTUK YILDIZ
Yüksek Lisans
İngilizce
2022
Makine MühendisliğiSabancı ÜniversitesiÜretim Mühendisliği Ana Bilim Dalı
DOÇ. DR. LÜTFİ TANER TUNÇ
PROF. DR. ERHAN BUDAK
- Diesel motorları yakıt püskürtme sistemlerinin dinamik simülasyonu
Başlık çevirisi yok
İRFAN KARAGÖZ
Yüksek Lisans
Türkçe
1986
Makine MühendisliğiUludağ ÜniversitesiMakine Mühendisliği Ana Bilim Dalı
PROF. DR. OĞUZ BORAT
- Ağızlık açma mekanizmalarının tasarımı
Başlık çevirisi yok
RECEP EREN
Yüksek Lisans
Türkçe
1987
Tekstil ve Tekstil MühendisliğiUludağ ÜniversitesiTekstil Mühendisliği Ana Bilim Dalı
DOÇ. DR. HALİL R. ALPAY
- İki katlı pamuk ipliklerinden dokunan kumaşlarda örgüye bağlı olarak maksimum atkı sıklığının değişimi üzerinde bir araştırma
Başlık çevirisi yok
MELTEM ASLI NARTER
Yüksek Lisans
Türkçe
1985
Tekstil ve Tekstil MühendisliğiEge ÜniversitesiTekstil Mühendisliği Ana Bilim Dalı
DOÇ. DR. GÜNGÖR BAŞER