Prediction of Strap Joint Design Margin in After Treatment System
Aniket M Pawar1, Kishor P Deshmukh2
1Aniket Pawar, Department of Design Engineering, Pimpri Chinchwad College of Engineering, Pune (Maharashtra), India.
2Kishor Deshmukh, Applied Mechanics Engineer-Technical Specialist, Cummins Technical Center India, Pune (Maharashtra), India.
Manuscript received on 29 July 2023 | Revised Manuscript received on 08 August 2023 | Manuscript Accepted on 15 August 2023 | Manuscript published on 30 August 2023 | PP: 28-35 | Volume-12 Issue-9, August 2023 | Retrieval Number: 100.1/ijitee.I97120812923 | DOI: 10.35940/ijitee.I9712.0812923
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: The automotive vehicle has an exhaust system, also known as the after-treatment System. It consists of various components, including Diesel Oxidation Catalysts (DOC), Diesel Particulate Filters (DPF), and Selective Catalytic Reduction Systems (SCR), among others. These components are mounted in the chassis with the help of strap joints. The strap joints provide flexible and serviceable connections between ATS bodies and chassis. The strap joint assembly consists of a T-bolt, trunnion, and nut, all of which are secured by a strap. As the nut tightened, the tension induced in the strap clamped the body. If the tension in the strap is insufficient, it may cause the joint to fail. The failure can be characterised by the yielding of material, slipping, and separation of the body. The strap joint should be designed to avoid these kinds of failures. This paper presents work on calculating the design margin using both analytical and FEA methods. The failure modes addressed in this paper are the yielding of the strap joint due to the applied preload on the T-bolt, slipping, and separation of the ATS body from the strap due to the application of dynamic loads, such as acceleration G loads in multiple directions. The acceleration load is calculated from the PSD profile. For calculating design margins using the FEA method, a nonlinear analysis is performed, followed by a PSD analysis to estimate the reaction forces on the bracket. These reaction forces are used to calculate slip and separation margins. The tests were conducted under similar conditions on a shaker table, and the results from both analytical and FEA methods were correlated with test observations to validate the proposed method for calculating the strap join design margin.
Keywords: After Treatment System, Design Margin, Hoop Stress, Strap Joint
Scope of the Article: Design and Diagnosis