Implementing end-to-end Simcenter solutions for test-based durability engineering

Tuning vehicles to local custom needs

In 2017, Nissan enjoyed a record year with 5,820,000 cars sold globally. That year, Renault-Nissan Alliance became the world’s leading seller of passenger vehicles, surpassing Volkswagen.

Nissan’s brand awareness and recognition is at its zenith. In fact, YouGov BrandIndex, which measures the public perception of thousands of brands in Europe, reports that Nissan is the fifth-ranked automobile supplier (of 38) for United Kingdom (UK) consumers.

To continue increasing brand perception, as well as improving the quality ranking, Nissan sets high standards in regard to engineering quality and reliability, it is essential to understand and address the needs and requirements of its local customers. The role of the Nissan Technical Centre in Europe (NTCE) is to support Nissan’s reputation and ensure that performance attributes of new vehicle designs and concepts meet European consumer expectations. Nissan Technical Centre Spain (NTCE-S) is a center of excellence for the design and development of vehicles manufactured across Nissan’s European production plants, focusing on key activities such as powertrain development, light commercial vehicle engineering and testing.

Nissan is committed to offering its European customers the highest standards of quality and reliability. This is one of the reasons why NTCE-S invested in Simcenter™ software solutions from Siemens Digital Industries Software for test-based durability engineering to bring its engineering capabilities to the next level.

Durability is key

The main role of the function and durability department at NTCE-S is to validate the functional performance of an engine’s components over the vehicle’s lifecycle. To assess performance, the team conducts extensive tests on components fitted on NTCE’s engine dynamometer (dyno). It also evaluates the component’s performance in a full assembly configuration, where the complete vehicle is positioned on the chassis dyno. Finally, the team puts passenger cars and light commercial vehicles (for example, pick-up segment) through fatigue tests, either on the test bench or the test track.

A large number of the tests performed by the function and durability team are durability tests. Durability is an important performance attribute of passenger and light commercial vehicles. In the light commercial vehicles market segment, consumers are inclined to select a brand they trust will support their daily needs.

“Durability is extremely important,” says Arturo Barreu, powertrain durability test engineer, function and durability department, NTCE-S. “In Europe, this attribute is closely associated with the perception of quality. As the demand for quality increases, we need to confirm the durability of our vehicles. Consumers expect vehicles will not break down after only one year, but up to 20 years.”

Other attributes such as ride and in-vehicle comfort, engine power and fuel efficiency are also important in the vehicle’s design. The role of a durability engineer has become more complex as durability engineering teams need to take more parameters into account when conceiving and testing components, subsystems and full systems of next-generation vehicles.

Streamlining processes

One of the steps the team took to improve durability engineering was to invest in solutions from the Simcenter portfolio. With its portfolio, Siemens Digital Industries Software helps streamline the engineering process by offering an end-to-end solution for test-based durability engineering.

A complete durability test campaign encompasses measurements on the engine dyno, followed by measurements on the chassis dyno, after which the test team moves to the test track. As the engineers are required to move the test equipment from one location to the next and to instrument the test item anew, they appreciate the portability and flexibility of Simcenter™ SCADAS hardware.

“We use Simcenter SCADAS for all our data acquisition tasks,” says Barreu. “It is a portable system which is very compact. It is also versatile, adjusting to our needs. With it, we can acquire different types of data such as acceleration or strain, using the same equipment. Our Simcenter SCADAS data acquisition systems total more than 100 channels, which we can easily transport from the engine dyno to the chassis dyno and to the test track and back.”

Beyond data acquisition, the team streamlined its durability engineering process by relying on Simcenter Testlab™ software for load and fatigue analysis. The software effectively supports every step of a testing campaign, from data acquisition to load classification and fatigue life prediction. Moreover, it forms part of a platform dedicated to multiphysics test-based performance engineering and, as such, better helps balance the contribution of various performance attributes such as acoustic, comfort and durability, combined with low weight and fuel economy, to the overall perceived quality and reliability.

The function and durability department’s main responsibility is to test and validate the functional performance of enginerelated components. The engineers, meanwhile, acquire, analyze and compare test data on a large number of components and engine subsystems. They combine the outcome of durability analyses, such as time at level, rain flow counting, range pair counting, level crossing, and fatigue life prediction, with typical noise, vibration, and harshness (NVH) analysis results, which can include peak hold spectra, order sections, colormaps, and many more. All durability and NVH data are acquired using the same Simcenter SCADAS hardware, and the analysis is performed in a single software environment, making it a very efficient process for the engineering team.

“The key challenge that we are confronted with is the consolidation of our knowledge,” says Barreu. “We have to test more components now than ever before. These components are also of a different nature. We test more and more electronic components and less mechanical parts. The collaboration with Siemens is essential to adapt to these changes and to validate these new components.”

For the validation of the component on the test rig, the team uses Simcenter Testlab to synthesize an equivalent damage profile and to consequently emulate the damaging events encountered during test track measurements on the rig. This highly efficient process significantly accelerates testing by realistically simulating the damage experienced by the component during the operational life of the vehicle.

NTCE engineers have found that Simcenter Testlab offers great stability, independent of channel count, making it easy for them to configure online analyses. The solution also provides fast and error-free data postprocessing thanks to the Process Designer functionality and offers immediate, clear reporting.

“Simcenter Testlab is our preferred tool for durability validation,” says Barreu. “It is easy to configure and allows us to automate processing. It is also a very good software for quick reporting and data sharing with our colleagues.”

The outcome of the tests produce reliable data that can be endlessly manipulated to deliver deep engineering insight into the fatigue behavior of the components. This data supports the definition of further tests or feeds the simulation models with trustworthy validated information.

“Simcenter Testlab offers an integrated end-to-end solution for load data acquisition and processing,” says Guillermo Gonzalez, function and durability senior engineer, NTCE. “The solution accelerates the delivery of critical durability insights when preparing for test rig campaigns or reliable simulations. It is faster, easier to use and robust.”