Summary: Compact microchannel heat exchangers (MCHEs) are an essential component to several clean energy technologies including hydrogen fueling stations and supercritical carbon dioxide (sCO2) Brayton cycles. MCHEs have exceptional thermal performance, high pressure containment capability, low cost, and compact size. However, their mechanical lifetime is not well understood. Studies have tried to establish guidelines for lifetime using analytical, experimental, and computational techniques; but the large variety of potential configurations, extreme experimental conditions, and computational cost of the coupled multi-physics simulations has limited their practicality. This challenge can be met with the expertise and HPC resources of a national lab to gain insights into localized mechanical stresses due to combined loading from pressure, thermal gradients, transient operation, and flow maldistribution. These insights will improve design sophistication and MCHE reliability, reduce construction material waste, and increase thermal operating efficiencies which will support a hydrogen economy and reduce the cost of electrical power production.