PSI - Issue 77

Vasco Gomes et al. / Procedia Structural Integrity 77 (2026) 559–566 Gomes et al./ Structural Integrity Procedia 00 (2026) 000–000

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2.3. Stamping forces The press was modelled to perform five consecutive operations as the sheet of metal passes through it. The SimulationX® software does not have the ability to model distributed loads, therefore concentrated loads were used to recreate the stamping conditions. Following the average distance between each station, these loads were separated by 350 mm and each curve had a maximum equal to the force applied in each station, just as shown in Fig. 2.

Fig. 2. Stamping loads discretisation for 3D rigid body model.

2.4. Pneumatic counterbalance system Mechanical presses commonly use a pneumatic system to counterbalance the weight of the slide, acting as an aid to reduce motor torque and prevent uncontrolled movement of the slide. The system includes two double acting pneumatic cylinders connected to the slide’s linear joint. One chamber in each cylinder is pressurized via a regulated source set to 9.5 bar (with ±0.8 bar variation), while the other vents to the exhaust. To prevent depressurisation, 270 L vessels are connected to each pressurised chamber. The key cylinder dimensions are listed in Table 1.

Table 1. Pneumatic system parameters. Parameter

Dimension

Unit mm mm mm

Piston diameter Rod diameter Maximum stroke

320

50

315

2.5. Contact elements The guiding system ensures the slide moves in a straight line, avoiding misalignment and, consequently, defective parts. There are 16 contact regions between the slide and the structure guides, each modelled with a contact element that calculates force based on the overlap area between components. Additional parameters are shown in Table 2.

Table 2. Contact definition parameters for the material RG7 white bronze. Parameters considering RG7 white bronze Dimension Unit Stiffness with relation to intersection area 10 N/mm 2 Damping in normal direction 0 Ns/m Sliding friction coefficient 0.07 - Limit velocity difference 0.1 m/s

3. 1D Model 3.1. Transmission system

The 1D model, Fig. 3, is simpler than the 3D one, but retains similarities, featuring two branches that distribute the weight of each component evenly. An external source is connected to the FMU block, followed by the reducer’s inertia and transmission ratio, then the drive shaft’s inertia. The branches are split: with the right having one gear transmission, and the left two. Each is followed by crankshaft inertias and a crank element converting rotation to linear motion. The masses (and their weight acting as force) are evenly divided between both branches.