DO-160 Simulations
We have posted a new training which shows a DO-160 type measurement of a 22 AWG twisted shielded pair, and compares the test results with simulation results.
DO-160 is a document that outlines a set of minimal standard environmental test conditions and corresponding test procedures for airborne equipment. Section 22 focuses on the lightning induced transient susceptibility, and describes test methods in order to verify the capability of equipment to withstand various test transients which represent the induced effects of lightning. DO-160 is the standard to follow for certification testing.
The measurement described below is for training purposes only. In actual DO-160 testing, waveforms defined in the DO-160 document should be used.
In this measurement, a double exponential current waveform resembling lightning component A, but with 400 mA amplitude, is injected onto the shield of the cable. The cable shield was grounded to an aluminum sheet placed 2 inches below the cable, such that the current path was from the cable shield to the aluminum sheet, back to the generator ground. The open circuit voltage (VOC) was then measured at the end of the cable opposite the injection point. For this configuration, the only way for any current and voltage to couple to the twisted pair inside the shield is through the shield transfer impedance. The schematic of the measurement is shown below. A full demo video of the test, test setup, and the simulation can be viewed here. The demo can be downloaded from the training page.
The corresponding model is a simple model of a cable above a metal sheet created in EMA3D integrated with MHARNESS. The training goes through all of the steps for creating the model. Once the model is created and the simulation completed, the comparisons of the measured and modeled VOC should look like this:
