Safety and optimization of preventive maintenance are priorities for IEME Brasil and LAEDE when it comes to evaluating their customers’ metro rail systems. To achieve this, the company relies on cutting-edge technologies and methodologies, the result of exchanges and monitoring of studies in some of the most advanced technological centers on the subject. One of the resources adopted by IEME for this purpose is the instrumented wheelset calibrator, studied in Italy by the Università degli Studi di Firenze, Sapienza in Rome and the Polytechnic of Milan, institutions visited by the company.

But what is the instrumented wheelset calibrator?

“The calibrator is a bench designed to apply existing loads on the permanent track onto an instrumented wheel set with the aim of correlating wheel-rail contact forces and deformations. To this end, electrical resistance strain gauges, hydraulic jacks, actuators and various load cells are used, in addition to a structure capable of supporting such loads”, explains engineer Tiago Juliani, Engineering coordinator at IEME Brasil.

There is a variety of information obtained by the calibrated instrumented wheelset. With the passage of the instrumented wheelset, the wheel-rail contact forces and the L/V relationship (lateral force / vertical force of the wheel) are obtained along the entire path of the train, which may indicate problems both on the permanent track as well as in the rolling stock, such as geometric imperfections in the track, welding defects, failures in railway components, poor maintenance of tracks and wheels, among others. Furthermore, the operational risk of the line is assessed with the L/V ratio.

Therefore, the calibrator is adopted whenever a new measurement campaign is carried out with the instrumented wheelset and, if the same previously instrumented wheelset is used, there has been a certain mileage between one campaign and another.

Versatility and security

Elastomers are polymeric materials with viscoelastic properties, which means they can be stretched and deformed under tension and then return to their original shape when the tension is removed. This unique ability makes these materials extremely versatile and valuable across multiple industries.

In the context of civil and railway construction, elastomers play a crucial role. They are used in large works and railway systems for a series of applications, ranging from shock absorption to vibration isolation. These properties are fundamental to ensuring the safety and adequate performance of structures and systems.

However, to ensure that these elastomers meet the necessary quality and performance standards, it is essential to carry out a series of rigorous tests defined by international Technical Standards. This is where LAEDE – Acoustics and Dynamic and Static Testing Laboratory comes in.

LAEDE, part of IEME Brasil, has extensive experience in high-capacity static and dynamic mechanical testing, which plays a key role in the evaluation and certification of elastomers used in a variety of applications.

The tests carried out by LAEDE include the evaluation of the mechanical and performance properties of materials. This includes quasi-static tests of vertical and shear stiffness, dynamic tests of free and forced vibration, permanent loading, fatigue (mechanical aging) and obtaining the damping coefficient. Additionally, the laboratory is capable of reproducing specific conditions in greenhouse and water environments, which is crucial for testing elastomers in real-world conditions.

The importance of these tests cannot be underestimated. They ensure that elastomers function as expected, providing the necessary shock absorption, vibration isolation and flexibility in various applications. This rigorous assessment also helps identify any wear or degradation over time, ensuring the safety and durability of these materials.

LAEDE is part of the Brazilian Network of Testing Laboratories (RBLE) and is a laboratory accredited by Cgcre in accordance with ABNT NBR ISO/IEC 17025. This means that the tests meet the highest standards of quality and technical competence. Therefore, when choosing LAEDE to carry out these tests, you can be confident that you are working with experienced and certified professionals.

See more on the LAEDE website.