DEĞER SEÇİMİNİN VOKSEL TABANLI SONLU ELEMAN MODELLERiNiN DOĞAL TİTREŞİM DAVRANIŞLARI ÜZERİNDEKİ ETKİLERİNİN İNCELENMESİ - INVESTIGATION ON EFFECT OF TRESHOLD VALUES ON NATURAL VIBRATION BEHAVIOR OF VOXEL BASED FINITE ELEMENT MODELS

DEĞER SEÇİMİNİN VOKSEL TABANLI SONLU ELEMAN MODELLERiNiN DOĞAL TİTREŞİM DAVRANIŞLARI ÜZERİNDEKİ ETKİLERİNİN İNCELENMESİHasarsız görüntüleme teknikleri ile elde edilen dataların temel girdi olarak kullanıldığı voksel tabanlı sonlu eleman metotları tıp, mekanik ve malzeme mühendisliği gibi çeşitli branşlarda karşılaşılan mikro ve nano ölçekteki problemlerin çözümlenmesinde artan bir kullanım alanına sahiptir. Voksel tabanlı sonlu eleman modelleri bilgisayarlı tomografi (BT) ve manyetik rezonans (MR) gibi görüntüleme tekniklerinden elde edilen görüntü kalitesinden doğrudan etkilenmekte olup yapılan bu çalışmada, söz konusu etkilerin mikro ölçekte kompleks geometriye sahip yapıların doğal titreşim analizi üzerindeki etkileri incelenmiştir. Bu amaçla, vertebral trabecular kemik dokusunun Mikro-BT görüntü datası kullanılarak aynı dilim kalınlığına sahip sadece eşik değerleri gözün yanılma aralığı sayılabilecek değerlerde değiştirilmiş üç modelin doğal titreşim modları incelenmiştir. Söz konusu sonlu eleman modellerinin ortaya koyduğu doğal titreşim davranışları sadece sayısal değer farklılıkları değil, bunun yanında aynı mod numarasına sahip olmalarına rağmen, mod şekilleri ile en büyük şekil değiştirmelerin oluştuğu yerlerin aynı olmadığı görülmüştür.INVESTIGATION ON EFFECT OF TRESHOLD VALUES ON NATURAL VIBRATION BEHAVIOR OF VOXEL BASED FINITE ELEMENT MODELSVoxel based finite elements methods (VB-FE) in which obtained data by non-damaged imaging techniques are used as main input have an increasing area of usage while solving micro and nano scaled problems in several fields as medicine, mechanical and material engineering. Voxel based finite elements models are directly effected by image quality obtained by imaging techniques as computed tomography and magnetic resonance. In this study, effects of related subjects on natural vibration analysis of structures which have micro scaled complex geometry are investigated. For this purpose, natural vibration modes of three models which have same slice thickness and whose thresholds are changed in small values by using MicroBT imaging data of vertebral trabecular bone tissue are studied. Natural vibration behaviors of related finite elements models have numerical differences. Besides, although they have same mode numbers, the places where mode shapes and biggest deformations occur are also different.

Anahtar Kelimeler:

Voksel tabanlı sonlu elemanlar metotu, Dilim Kalınlığı, Poroz Malzeme, Doğal Frekans

Değer Seçiminin Voksel Tabanli Sonlu Eleman Modellerinin Doğal Titreşim Davranişlari Üzerindeki Etkilerinin İncelenmesi

Voxel based finite elements methods (VB-FE) in which obtained data by non-damaged imaging techniques are used as main input have an increasing area of usage while solving micro and nano scaled problems in several fields as medicine, mechanical and material engineering. Voxel based finite elements models are directly effected by image quality obtained by imaging techniques as computed tomography and magnetic resonance. In this study, effects of related subjects on natural vibration analysis of structures which have micro scaled complex geometry are investigated. For this purpose, natural vibration modes of three models which have same slice thickness and whose thresholds are changed in small values by using MicroBT imaging data of vertebral trabecular bone tissue are studied. Natural vibration behaviors of related finite elements models have numerical differences. Besides, although they have same mode numbers, the places where mode shapes and biggest deformations occur are also different

Keywords:

Voxel based finite elements method, slice thickness, porous material, natural frequency,

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