Context:
The protection of military vehicles is evaluated according to a document produced by NATO countries called STANAG for Standardization Agreement. STANAG 4569 is about the protection Levels for Occupants of Logistic and Light Armored Vehicles. Several levels of threats are referenced up to 10 kg of TNT equivalent. A reference soil called STANAG soil is defined. The Altair Solutions to satisfy this regulation are described here: https://community.altair.com/community?id=altair_file_exchange_article_view&sysparm_article=KB0119697.
In order to assess the survavibility of the occupants a specific safety criteria called DRIz is used.
Goal:
The aim of this article is to decribe and share a Twin Activate Digital Twin that allows to evaluate the DRIz criteria.
What is DRIz:
Twin Activate Digital Twin of DRIz:
Altair has developed a digital twin to emulate the sping damper system and hence evaluate the DRIz value :
How to use the Digital Twin:
0. Open the Digital Twin DRIz_Calculation_Digital_Twin.scm in Twin Activate
1. Click on the box "accel_m_s2".
A csv file with 2 columns should be selected as input:
- Column 1: time in s
- Column 2: Acceleration in meters per seconds scare.
2. Click on "Run":
3. Review the DRIz curve: The max value should be considered for the regulation
Digital Twin Validation:
The following publication http://www.ircobi.org/wordpress/downloads/irc12/pdf_files/48.pdf has been used to validate the Digital Twin. The publication provides the expected values of DRIz with some very simple pulses input:
The pulse a, b & c have been tested with the digital twin and each time the expected value of 17.7 was found along with the good shape of the curve.
Attachments:
The DRIz digital twin is attached to this knowledge base article as DRIz_Calculation_Digital_Twin.scm
The different pulses used for the validation are also attached to this article (curve_a.csv, curve_b.csv & curve_c.csv). They can be used as an example for the input curve.