Dynamic Stress Analysis in HALT/HASS Testing
Validation testing
Multihog Ltd, headquartered in Dundalk, County Louth, is an Irish manufacturer of innovative, multifunctional tractors and compact sweepers designed for year-round maintenance across various sectors, including airports, local authorities, highway maintenance, ground care and construction.
The company required a validation testing on a device designed for EV sweeper and tractors. Due to the intended operating environment, the system would be exposed to high duration of intense vibration. There were concerns that sustained vibration could lead to component loosening, failure of soldered joints, and damage to sensitive electronic components. In addition, certain components may be susceptible to specific frequency ranges, increasing the risk of resonance and amplified stress within the system. A key requirement was to develop a realistic understanding of the vibration environment and assess the durability of the DUT (Device under testing) under these conditions.
Through the partnership, CREDIT Technology Gateway carried out a structured testing programme. The work began with real-world data acquisition, in which the DUT was mounted on a test setup and driven over uneven terrain to replicate operational conditions. During this phase, vibration data was recorded using an SRO measurement system, capturing the G-forces experienced during operation.
Pseudo-random vibration profile
The recorded data was processed using a custom Python script to generate a frequency spectrum of the vibration input. This allowed the team to identify dominant frequencies and potential resonant behaviour within the system, as well as assess how specific components, including electronic chips, respond to different frequency ranges.
Using this data, a pseudo-random vibration profile was developed to replicate the measured conditions in a controlled laboratory environment. The DUT was subjected to forced vibration across a range of frequencies and amplitudes, including high-intensity levels beyond standard operating conditions, to expose potential weaknesses.
To ensure realistic testing, a load simulator was used so that the DUT remained operational during vibration. The testing programme incorporated elements of Highly Accelerated Life Testing (HALT) and Highly Accelerated Stress Screening (HASS), allowing the team to identify failure modes such as component loosening, weak solder joints, and resonance-related issues. Relevant industry considerations, including environmental and combustibility requirements, were also considered.
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Irish Company
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Innovation Partnership Feasibility Study
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Structured testing programme
“Multihog had the opportunity to participate in an Innovation Partnership Feasibility research project focused on vibration testing of electronic equipment, and it was an exceptionally valuable experience. The project was both rigorous and highly relevant, addressing real-world challenges in ensuring the reliability and durability of electronic systems under mechanical stress.”
Jim McAdam – MD
Multihog Ltd & CREDIT Technology Gateway partnership
As a result of this collaboration, Multihog Ltd gained valuable insights and a clear understanding of how the DUT performs under representative vibration conditions. The project identified critical frequency ranges and potential failure modes, enabling targeted improvements to the design.
The testing approach provided a repeatable methodology for future validation and reduced the risk of in-service failure. As a result, the company is better positioned to deploy the system in external environments with increased confidence in its reliability and performance.