PSI - Issue 79

446 Giulia Morettini et al. / Procedia Structural Integrity 79 (2026) 440–448 In this color-based representation, red zones ( ��� � 1 ) identify regions where the estimated component lifetime is lower than the reference threshold and are therefore unsuitable for mounting; yellow areas ( 0.5 � ��� � 1 ) represent critical regions, located near the safety limit; whereas green zones ( 0.5 � ��� ) correspond to areas suitable for cTohme pd oe vneelnotppelda ct oe mo l eanl lto, we nsstuhrei nugs earnt aocdceefpi nt aebclue ssttormu cst ua freatlystahf er et ys hmoal dr gs ,i ne .n a b l i n g a u t o m a t i c f i l t e r i n g o f t h e b o a r d rbeegc ioomn se sc ao nn sei fdf ee cr et idv emdoescti sai op np -rsoupprpi aotret at oc oc ol , rudsi enfgu lt od udrei ns igg tnh er el qa yu oi ruetmpehnatsse. fIonr ti hd iesnwt i fayyi ,n tghteh et oot pa lt i dmaaml aa rgeea ms faopr component positioning and for reducing the risk of vibration-induced mechanical failures.

Fig. 6. Example of total PCB damage map showing areas of increasing fatigue risk: red � non-permissible � , yellow � critical � , and green � safe � regions. 4. Closed-Loop Scenario It is worth noting that, once the optimal position for mounting the first component on the board has been identified (as shown in Fig. 7a), the tool can operate according to a closed-loop logic. In this scenario, the already assembled board is reintroduced into the analysis workflow as a new input for the evaluation of the next component to be placed. In this way, the iterative process progressively updates the structural model of the PCB, taking into account the presence and dynamic influence of the components already mounted. These effects can be incorporated through different modal and structural updating methodologies (Morettini et al. (2022)), developed by the same authors, which allow the dynamic response of the system to be adapted as new components are added. The influence of the previously installed components is also evident in the final phase of the workflow, as illustrated in Fig. 7b, where the areas occupied by existing components are automatically highlighted as exclusion zones for subsequent placements. This closed-loop approach enables a realistic simulation of the progressive population process of the PCB, ensuring that each new layout decision respects both the mechanical and vibrational constraints of the system and the geometric and functional requirements, up to the complete assembly of the board.