Simulation of Stress Distribution Depending on Filling and Discharge Conditions in Wheat Silo with Different Wall Thickness

Abstract

The design and development of commercially planned silos requires a strong understanding of their structural performance and loads. A limited number of studies have investigated the effect of stored products on silos. For this reason, Silo 1 and Silo 2 models with hopper base and steel construction with different wall thickness for commercial purposes were designed for storage wheat grain. For this purpose, the usability of 3, 4, 5, 7, 8, 9 and 10 mm wall thicknesses for safe storage was investigated in two different models of silos with 1306 tons and 610 tons of storage capacity. First of all, pressure loads on the model silo walls are calculated according to Eurocode 1. Then, the full-scale finite element model (FEM) of wheat silos was developed and the silos were simulated with ANSYS® software according to the filling and discharge of the product. The stored wheat and silo body interactions were modeled with minimal simplification, taking into account the characteristics of both wheat and steel silo. As a result of the research, the pressure loads in the filling and discharge conditions for both silo models increased from the top of the silo to the discharge opening. It has been determined that lower wall thicknesses are subjected to more pressure load under filling and discharge conditions. While the maximum pressure loads occurred in the funnel area in Silo 1, they occurred in the transition zone in Silo 2. As a result of ANSYS simulation, the maximum deformations for both silo models were determined in the transition zone and just below this zone. According to the results of the modal analysis, it was observed that the frequency values increased with the increase of silo wall thickness. In the light of these data, it can be said that safe and secure storage is Silo 1 and 8 mm wall thickness.

Keywords

• Steel silo
• filling
• discharge
• pressure loads
• stress

Farklı Cidar Kalınlıklarına Sahip Buğday Silosunda Doldurma ve Boşaltma Koşullarına Bağlı Olarak Gerilme Dağılımının Simülasyonu

Öz

Ticari amaçlı planlanan silolarının tasarımı ve geliştirilmesi, yapısal performansının ve yüklerinin güçlü bir şekilde anlaşılmasını gerektirir. Bu çalışmada sınırlı sayıda araştırma, depolanmış ürünlerin silolar üzerindeki etkisini araştırmıştır. Bu nedenle buğday tahılının depolaması için huni tabanlı, ticari amaçlı farklı cidar kalınlığına sahip çelik konstrüksiyonlu Silo 1 ve Silo 2 modelleri tasarlanmıştır. Bu amaçla araştırmada 1306 ton ve 610 ton depolama kapasitesine sahip iki farklı model siloda 3, 4, 5, 7, 8, 9 ve 10 mm cidar kalınlıklarının güvenli bir depolamada kullanılabilirlikleri araştırılmıştır. Öncelikle Eurocode 1’e göre model silo cidarları üzerindeki basınç yükleri hesaplanmıştır. Daha sonra buğday silolarının tam ölçekli sonlu eleman modeli (FEM) geliştirilmiş ve silolar ürünün doldurulması ve boşaltılması durumuna göre ANSYS® yazılımı ile simüle edilmiştir. Depolanan buğday ve silo gövdesi etkileşimleri, hem buğdayın hem de çelik silonun karakteristik özellikleri gözönüne alınarak, minimum basitleştirme ile modellenmiştir. Araştırma sonucunda her iki silo modelinde doldurma ve boşaltma koşullarındaki basınç yükleri silonun tepe noktasından boşaltma ağzına doğru artış göstermiştir. Doldurma ve boşaltma koşuluna göre düşük cidar kalınlıklarının daha fazla basınç yüküne maruz kaldıkları belirlenmiştir. Maksimum basınç yükleri Silo 1’de huni bölgesinde ortaya çıkarken Silo 2’de geçiş bölgesinde ortaya çıkmıştır. ANSYS simülasyonu sonucunda her iki silo modeli için maksimum deformasyonlar geçiş bölgesinde ve bu bölgenin hemen altında tespit edilmiştir. Modal analiz sonuçlarına göre silo cidar kalınlığının artması ile frekans değerlerininde arttığı gözlemlenmiştir. Çalışma sonucunda elde edilen veriler ışığında güvenli ve emniyetli depolamanın Silo 1 ve 8 mm cidar kalınlığında olduğu söylenebilir.

Anahtar Kelimeler

• Çelik silo
• doldurma
• boşaltma
• basınç yükleri
• gerilme

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