From wind and water to earth and sun, Structural Integrity helps clients harness the power of nature. We have developed and applied advanced technologies to capture energy from a variety of renewable sources – and to keep equipment operating reliably. With decades of field experience and technical know-how, Structural Integrity is uniquely qualified to serve the fast-moving renewable energy sectors such as the hydro, wind and solar markets.
While wind turbines have a high level of reliability, they can experience progressive damage and failure like any machine due to design shortcomings, fabrication flaws, and operational loads. Components such as gears, shafts and bearings can experience wear and fatigue, composite (fiber reinforced) blades can experience fatigue and environmental degradation, tower structures can experience cracking due to vibration and concrete pedestals can also suffer degradation. As the wind turbine fleet ages, damage accumulates that can lead to catastrophic failures and long, expensive operational downtimes. Structural Integrity has experience in assessing the failure modes, their associated rates, and the appropriate maintenance strategies needed to address them. We have developed the expertise and tools to help our clients inspect, assess fitness-for-service (FFS), perform failure analysis, and support the implementation of optimum life management programs for the safe continued operation of wind turbines.
When the main shaft of a wind turbine failed catastrophically the farm operator wanted to know the root cause and if this was a serial issue within the wind farm. SI performed inspection and fractographic analysis which determined that a specific feature in the shaft near the hub connection initiated a fatigue crack. Using this information Structural Integrity's NDE team developed a customized inspection solution and applied it to several wind turbines in the farm. The results showed that this feature was not present on other turbines allowing the operator to be confident in the integrity of their main shafts.
A wind turbine suffered a blade failure, causing contact between the failed blade and tower which produced a small crease in the tower. Structural Integrity engineers assessed the extent of local damage to the tower, and created a finite element model of the tower. Analysis was done applying design loads, including operating conditions and wind load. The analysis showed the tower retained sufficient integrity so that the repaired wind turbine could operate safely without modifications.
Structural Integrity's primary involvement in the hydroelectric industry has been in providing engineering services on a range of areas within critical parts of the structure and power house. These services include evaluations of concrete and earthen structures, seismic analyses, soil-structure interactions, and soil fragility, as well as engineering related to power house equipment and penstocks. We have a wide variety of services and capabilities which include comprehensive asset management, code evaluations, failure analysis and vibration monitoring, and have inspected and/or evaluated over eighty penstocks throughout North America. We bring an array of talented experts, as well as models and tools, which can be employed to manage assets and address complex issues encountered in the hydroelectric industry.
Structural Integrity’s proprietary in-house concrete FEA code models the non-linear behavior of concrete which allows us to capture the ultimate structural behavior for loading conditions that exceed their original design basis. We have evaluated and renovated historic concrete dam infrastructure and saved utilities significant budgetary dollars in minimizing renovations and avoiding their replacement.
Risk assessment methodology for dams, including all hazards and failure causes (flooding, seismic, static, seepage, aging, etc.), failure modes (e.g., overtopping, piping, slope instability, liquefaction) and their consequences (including probabilistic flood routing and damage assessments).
Structural Integrity has been helping hydro owners for decades in the development of assessment plans, the determination of material properties, wall loss determination, fatigue evaluation, and other critically important safety and efficiency considerations.
Probabilistic studies for all types of hazards, including flood hazard assessments (PFHA) [not only probable maximum flood (PMF) and probable maximum precipitation (PMP), but also the complete array of hazard and likelihood levels] and probabilistic seismic hazard assessments (PSHA) [including development of seismic hazard curves and time histories for dam safety evaluations].
We have provided numerous soil-structure-interaction analyses for both concrete and earthen dams subject to seismic input loading. Structural Integrity utilizes the best soil fragility experts in the industry to evaluate slope stability, soil-structure-interaction, and the stability of earthen dams.
Structural Integrity has provided support and engineering services to the power industry for more than 30 years, and have transformed that experience and expertise into an integrated, multidisciplinary approach that combines engineering analysis, advanced nondestructive examination (NDE), materials evaluation, repair technologies,and data management to attain the best possible solutions for plant owners and operators. Structural Integrity offers advanced NDE, metallurgy, and engineering analysis for hydroelectric turbine evaluations.
The seismic hazard risk for many areas of the country have increased and Structural Integrity is well suited to perform stability analysis of both concrete and earthen dams. We have provided design solutions to renovate or to bring existing infrastructure into compliance for safety with current seismic demands.
Utility-scale solar projects to date have typically used Concentrated Solar Power (CSP) technology. These facilities generate solar power by using mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a relatively small area of heat transfer surface to heat a working fluid that is then used in a typical thermodynamic cycle (such as a steam cycle) to generate electricity.
Beyond the solar field components (mirrors), the other components and systems are technologies found elsewhere in the power generation industry – components and systems well understood by Structural Integrity. Components include tubing, headers, piping, heat exchangers, steam turbines, and generators typical of the other power plants that Structural Integrity serves on a daily basis. And the challenges with these components, including their degradation and failure over time, are similar or the same as that seen in conventional power plants, with the increased challenges of daily thermal cycles, cloud passage, and rapid ramp rates during startup and shutdown.