Page 14 - MetalForming July 2019

Tech Update
of kinematic hard-
ening, mainly a tran-
sient softening of
sheet material and,
more importantly,
degradation of
Young’s modulus,
says Demiralp,
increases the accu-
racy of springback
prediction in sheet
metal forming sim-
ulations. Isotropic
hardening does not
consider the
Bauschinger effect,
thus lowering the quality of springback prediction.
AutoForm has developed and implemented its own user-friendly kinematic hardening model, validated against physically determined cyclic tension-compression curves, as well as springback measurements. As a result, simulation provides reliable springback prediction even for complex geometries and materials, Demiralp says.
At Atlas Tool, stamping of the rear cab reinforcement consist of multiple operations, including drawing—with stake beads used to stretch the sheet during the last few millimeters of draw stroke—followed by two trimming operations and a final operation to measure springback. Setting up the simulation of these and any other operations with the correct process, die conditions, material properties and control parameters to accurately reflect the physical manufacturing process is essential to obtain reliable simulation results. Reliable springback results from a repeatable process help contribute to successful compensation that will reduce or eliminate tool recuts during die tryout.
The simulations produced springback-prediction results, with draw tools compensated accordingly in order to produce parts compliant with defined and desired dimensional tolerances for the final reinforcement part (Fig. 2). The simulated springback results, employing kinematic hardening modeling, compared closely with actual measurements (Fig. 3), report Demiralp and Broadworth, noting that the results were significantly better than those based solely on isotropic hardening.
AutoForm Engineering USA, Inc.: www.autoform.com
New Controls for AP&T Presses and Lines
AP&T has introduced a new-generation control sys- tem designed to simplify use of presses, automation equipment and production lines. The upgrade entails a comprehensive update of the Logos user interface, as well as functionality and hardware.
One new feature: larger screens. Users have access to 22-in. screens with full
HD for stationary PCs, and 7-in. screens for hand-held mobile panels. Both provide widescreen format and high resolution, with 2.5 times as many pixels as in previous offerings. Graphics have been developed to provide an improved overview of the displayed information as well as to facilitate navigation.
Describing improved functionality, “pre- viously, two clicks were needed to switch between the various machines connected to the system,” says Lars Prysander, AP&T development project manager and a pro- grammer for the new version. “We added an extra menu with shortcut keys, which means that only one click is needed to switch from one unit to another.”
The control-system renewal began in spring 2018 in conjunction with transition to Siemens’ new software platform, the TIA Portal. All of AP&T's Logos products and production lines are equipped with the latest generation of the user interface, with the latest CPU versions as well as system inputs and outputs.
AP&T: aptgroup.com
New Press Ideal for
Electric-Vehicle
Motor Laminations
As part of the company’s TechDay event at its headquarters in Göppingen, Germany, Schuler unveiled its Smartline EV 3.8 new high-speed blanking press, to be delivered the German company Waasner for the production of interlocked motor cores.
E-mobility, a highlighted topic at the TechDay event, centers on solutions for the expanding electric-vehicle market. To increase the efficiency of the electric-vehicle motors, the geometrics of electric motor lamination have become more complex, according to Schuler officials, leading to longer stamping dies. That is why the EV 3.8 features a slide length of 3.7 m as compared to the previous length of 2.7 m, and can process strip in widths to 630 mm.
In addition, lamination material thick- ness has decreased, with current thickness defined as 0.25 to 0.275 mm, claim the
Fig. 3—This scan of the actual physical panel matches the predict- ed panel that included consideration of kinematic hardening properties in addition to isotropic hardening properties, thus affirming the effectiveness of such simulation.
12 MetalForming/July 2019
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