Utmattningsanalys av malmvagnsram
Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
The mining group Loussavaara Kiirunavaara AB manufactures and supplies processed raw materials of iron ore, which is a popular product around the world. To meet the high demand, a high production rate has to be maintained. LKAB has the goal of delivering at least 37 million tons of iron ore per year, by 2015.. LKAB has developed a new iron ore wagon, where a series of over a thousand wagons, have already been delivered by the company Kockums Industrier. In an effort to achieve the aforementioned production target, LKAB is looking into further maximize the ore loads on the wagons. The goal of this study is to analyze how the wagon behaves with a higher payload. In order to limit the scope of the study, limitations is made to the critical areas of the frame. The method is based on theoretical analyzes to determine the stress range, which occurs in the frame when the wagon is in operation. The stress results are then used along with the measurement data for determining the fatigue behavior of the frame. In broad terms the method of analysis are summarized as follows: 1. Problem formulation. 2. Computation. 3. Validation. The formulation of the problem is stated with the geometry, materials and the dynamics acting on the wagon, but also with the requirements; in this case, a fatigue life of at least 20 years for the frame of the wagon. The dynamics (load) acting on the wagon is determined primarily based on measurements, but a comparison is also made to the conservative given accelerations specified in the Swedish railway standard (reference ). The problem is then computed based on the problem formulation (1). A numerical stress computation is performed but also an analytically stress computation. The results from the numerical stress computation along with the measured number of load cycles (during operation) is then used to analyze the fatigue behavior of the wagon for 20 years of operation. As the stress calculation and fatigue calculations are performed the results are validated against laboratory tests. In comparison to the measured stress (at testing), the results from the numerical stress computation (static computation) are validated with good accuracy in the critical areas. The validation of the fatigue computation indicates that the result is on the safe side compared to the measured data. With the condition that the the load is increased by 10 tonnes and with the current operating conditions, the wagon is adequate for 20 years of life, with a good margin.
Place, publisher, year, edition, pages
2013. , 83 p.
Teknik, fatigue, FEM, Utmattning, FEA, Finita element, Simulering, Järnväg, Haigh, Eurokod, Palmgren Miner
IdentifiersURN: urn:nbn:se:ltu:diva-52957Local ID: a078f993-f152-470a-a20e-9a819de8542fOAI: oai:DiVA.org:ltu-52957DiVA: diva2:1026330
Subject / course
Student thesis, at least 15 credits
Mechanical Engineering, bachelor's level
Validerat; 20130620 (global_studentproject_submitter)2016-10-042016-10-04Bibliographically approved