Advanced Mechanical Testing Solutions
Efesto EPS is the engineering laboratory of Acta Srl, a center of excellence for innovation and research in mechanical testing.
In collaboration with the Department of Civil and Industrial Engineering (DICI) of the University of Pisa, Efesto has designed and built two advanced machines for RESONANCE FATIGUE TESTING.
This partnership combines academic and industrial know-how, offering solutions cutting-edge technologies in order to test and optimize mechanical components in business key sectors.
Our Partners And Collaborators
Resonant Rotating Test Bench
RRTB
The Resonant Rotating Test Bench (RRTB) is a cutting-edge solution designed for resonant fatigue testing of full-scale tubular specimens, including drill pipe sections and mechanical connections. This advanced testing machine operates based on the principle of mechanical resonance, inducing the specimen to vibrate at a frequency near its first resonance mode through an eccentric rotating mass. This controlled vibration continues until a fatigue fracture occurs, providing precise and reliable results.
The testing frequency is influenced by factors such as the specimen’s length, section properties, and lateral masses. Typically, the RRBT operates at around 25 Hz, enabling the system to complete 1 million fatigue cycles in approximately 11 hours with minimal energy consumption. This high-efficiency performance makes it ideal for long-duration fatigue testing.
The RRBT accommodates various pipe sizes to suit different testing requirements. Standard specimen dimensions include a length of 4.2 m (14 ft) and an outer diameter ranging from 100 mm (4 in) to 180 mm (7 in). Both the diameter and length can be adjusted to meet the target testing frequency, and the mechanical components of the test bench can be rescaled to support different pipe configurations.
Accurate load application is ensured through continuous monitoring of the bending load amplitude using calibrated strain gauges and advanced non-contact laser displacement sensors. Strain gauges are systematically calibrated before each test, guaranteeing precise control and measurement of the applied load.
Unlike conventional systems that apply a constant bending load, the RRBT introduces a patented feature that allows for variable bending load amplitudes during testing. This includes the application of fatigue block loadings, enhancing the simulation of real-world stress conditions. The system automatically adjusts its configuration to maintain optimal performance across varying load amplitudes.
The Resonant Rotating Test Bench (RRBT) represents the forefront of mechanical fatigue testing technology, combining efficiency, precision, and adaptability to meet the rigorous demands of industrial applications.
RITB
The Resonant In-plane Test Bench (RITB) is designed for resonant fatigue testing of full-scale tubular specimens having large section, such as Drill Collar connections. The bending load is generated by two pairs of counter-rotating eccentric masses located at the ends of two bending arms; so that the bending load oscillates within the horizontal plane.
The testing frequency depends on several factors, primarily the section properties of the tubular specimen being tested. However, this frequency typically ranges from 20 to 30 Hz.
The RIBT accommodates various pipe sizes to suit different testing requirements. Standard specimen dimensions include a length of 1.6 m (5.25 ft), while the outer diameter can range from 150 mm (6 in) to 230 mm (9 in).
The load control is achieved by adjusting the rotating frequency of the eccentric masses. Moreover, a finer tuning of the bending load is achieved by controlling the phase angle between the two counter-rotating eccentric masses. During the test, the stress amplitude is again measured by means of a strain gage or two (half-bridge) strain gages.
Mechanical Testing Services
Acta srl, in collaboration with DICI, offers advanced services such as: mechanical tests, finite element analyses, residual stress evaluation, mechanical friction power transmission and the possibility of developing projects customized for tests and mechanical systems.
MECHANICAL TESTING LABORATORY
Mechanical tests can be performed at the DICI Department, University of Pisa, such as on material samples extracted from the pipe specimens. Material characterization tests that can be conducted include tensile tests, fatigue tests, fracture mechanics tests, fatigue crack growth rate, and other custom tests with specific loads or geometries.
FE ANALYSIS
Finite Element (FE) analysis can provide strategic support to the experimental activity, and a large knowhow is available through the collaboration between the DICI Department of the University of Pisa, and ACTA Srl. The FE analyses can be focused on the tubular connection or any other mechanical components potentially tested at the facility.
TEST BENCH FOR FRICTION TRANSMISSION SYSTEMS
- Characterization of EP oils in piezoviscous conditions.
- Characterization of transmissibility of sliding forces in the field of mechanical power transmission.
- Automatic transmission response characterization.
RESIDUAL STRESS EVALUATION
Residual stresses can be measured using different techniques. In particular, the Hole-Drilling Method (HDM) is an effective, easy-to-perform, fast, and accurate methodology. The DICI Department, University of Pisa, has extensive experience with this technique and offers the required equipment at its facility.
Get in touch with us today to learn more about our custom testing services
Whether complex components or innovative solutions, Efesto EPS is ready to collaborate and meet specific needs from client engineering challenges.
