PSI - Issue 60

A. Bhardwaj et al. / Procedia Structural Integrity 60 (2024) 723–734 Abhimanyu Bhardwaj/ Structural Integrity Procedia 00 (2019) 000 – 000

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To comply with manufacturing constraints, the current design exclusively employs standard plates, U-rails, and strips, all inter-connected using cotter pins. In the furnace, heat transfer inside the furnace primarily occurs through radiation. However, there is a possibility that radiation emanating from the heating elements positioned at the top of the work zone may not sufficiently reach the jobs located in the bottom compartments. To address this issue, holes are drilled in the plates (refer Fig. 2), to facilitate the path for radiation. These holes also reduce the weight of the over-all structure. Additionally, slots (refer Fig. 2) are incorporated to allow for the insertion of thermo-couples inside the jobs for temperature monitoring purposes. Angle plates are utilized to firmly secure the job-carrier in place within the furnace (refer Fig. 2). 2.1. Design of Plates and Stiffeners The plates in the job-carrier design are carefully engineered to balance strength and rigidity while considering a conservative point load of 400 kg at the centre. The calculation takes into account fixed end-conditions and a factor of safety (FOS) 1.5 applied to the material strength at 1200 deg C, resulting in an allowable stress ( S ) of 267 MPa. Plate theory is used to determine the appropriate plate thickness using Eq. (1) and Eq. (2). Eq. (1) calculates the plate thickness based on the allowable stress ( S ) and applied load ( P ). Eq. (2) calculates plate thickness ( T ) or flexural rigidity ( D ) based on the allowed deflection ( Δ ), and plate radius ( a ). An iterative approach considering both strength and rigidity leads to a plate thickness of 5 mm, as illustrated in Fig. 3 (a). = 32 2 (1) = 2 16 ℎ , = 3 12(1− 2 ) (2)

(a)