Residual stresses’ magnitude generated by deposition, quenching stress, thermal stress operation temperature, and infiltration in the thermal barrier coating (TBC) of gas turbines was determined. A thermal barrier coating was manufactured by the deposition of two layers, CoNiCrAlY and yttria-stabilized zirconia (YSZ), on an AISI 304 stainless steel substrate. The CoNiCrAlY was deposited by using an HVOF gun and the YSZ by an atmospheric plasma spray (APS). The TBCs were heat-treated at 1250 °C, with a CMAS (CaO, MgO, Al₂O₃, and SiO₂) attack with a concentration of 10 mg/cm² for 6 h in order to evaluate the evolution of the state of residual stresses in the coating at a high temperature. Residual stresses were determined by employing the modified layer removal method for duplex coatings (MLRMDC), ANSYS Version R19.2, and the equations proposed by Noda et al. In the YSZ, the total maximum residual stresses were 139 MPa in compression, and in the CoNiCrAlY, the maximum residual stress was 214 MPa in compression. The factor that has the largest effect on the magnitude of residual stresses was the infiltration of the CMAS in the YSZ.

In this work, we present the effect of the amount of CMAS infiltration into YSZ of Thermal barrier coatings (TBC) on the magnitude of residual stresses. The (TBC) were deposited by thermal spraying of CoNiCrAlY (Bond Coat-BC) and YSZ (Top Coat-TC) powders. The deposition of the BC was through the high velocity oxygen fuel (HVOF) system. The TC was deposited via an atmospheric plasma-spraying gun (APS). The TBCs were heat treated at 1250 °C, with a CMAS attack at a concentration of 10 mg/cm².The attack exposure was for 2 and 4 hours respectively. In this evaluation, the measured parameter was the magnitude of the residual stress state in Yttria Stabilized Zirconia (YSZ). The residual stress profiles were obtained using the Modified Layer Removal Method for Duplex Coatings (MRCMRB) and the Noda equations. An increase of 26.446 MPa was determined for 2 hours of thermal treatment and 30.743 MPa for 4 hours.

In recent years, the demands of customers in the automotive sector have increased. The use of renewable sources for the production of electricity worldwide has intensified in recent years. In particular, the installed capacity for electrical production by wind turbines has doubled in the last 10 years, and it is projected that 48% of the world's electricity will be generated through renewable sources. The size of the wind turbines has grown to meet this need; for these turbines to generate more electricity, it is necessary for their rotors to capture a greater amount of kinetic energy from the wind. This is achieved by increasing the size of the rotors and, therefore, the size of the blades that make up the rotor. However, this increase in the size of the blades creates a logistical problem regarding their transportation to the installation site of the wind turbine. There is a solution to this problem, this consists of segmenting the blades, transporting the segments separately, and joining the blade at the installation site. However, all scientific knowledge is reserved because it has been developed by private companies. The present work consisted of designing a permanent coupling medium for a segmented blade of 60 m, which would allow the segmented blade to have a structural behavior equal or better than a conventional blade. Initially, a conventional blade with a weight of 22 tons and 60 m was studied structurally. The results of the structural analyses showed a first natural frequency of 0.658 Hz, a deflection of the tip of 5 m, and a maximum deformation of 2.974 µe. The results of the structural behavior of the segmented blade showed the same natural frequency as the conventional one, a lower deflection at the tip of 2.8 m, and a deformation of 3,529 µe, with a weight gain of 1,150 kg. These results demonstrate behavior similar to that of the conventional blade, with a lower deflection at the tip and only a weight increase of 5%. Keywords Optimization; Segmented blade; Wind Turbine; Conventional blade; Fiberglass; Design.

The structural segmentation of wind turbine blades offers advantages in transportation, manufacturing, and maintenance; however, it introduces interfaces that may compromise load transfer and fatigue performance. This study presents the experimental and numerical validation of a composite coupling system designed for small wind turbine blades compliant with IEC 61400-2 requirements. A 2 m representative section extracted from the mid-span region of a 9 m blade was manufactured using vacuum-assisted resin infusion and tested under static loading conditions. A detailed finite element model based on classical laminate theory and orthotropic material properties was developed to predict structural response. Experimental measurements showed a maximum tip deflection of 15 mm under the applied load, compared to 13.76 mm predicted numerically, corresponding to a deviation of 8.9%. Surface strain measurements obtained from eight strain gauges installed across the blade–coupling interface indicated maximum mean values of +632.4 με in tension and −664.2 με in compression, with no evidence of localized strain amplification at the instrumented locations. These findings demonstrate that fully composite permanent segmentation can preserve stiffness continuity while maintaining strain levels below reported fatigue initiation thresholds, supporting the structural feasibility of segmented blade architectures for small wind turbine applications.

A coupled thermo-mechanical probabilistic model for porosity prediction in robotic Cold Metal Transfer (CMT) welding is proposed and experimentally validated under industrial conditions. Unlike conventional energy-based approaches, the formulation explicitly incorporates fixture-induced geometric deviations through the effective stick-out relation ${SO}_0.$ A dimensionless fixture influence factor, $X_f$, is introduced to quantify mechanical–process interaction. A fractional factorial design followed by a reduced DOE-enabled separation of thermal and mechanical effects. Logistic regression integrating process energy descriptors and $X_f$ achieved strong predictive capability (AUC = 0.91; 95% CI: 0.87–0.94). The fixture influence factor exhibited the highest standardized effect (OR = 3.74), while a 1 mm increase in effective stick-out doubled porosity probability (OR = 2.10), demonstrating the dominance of mechanical coupling within the evaluated operating window. Industrial implementation confirmed model relevance: geometric stabilization reduced rework from 11.58% to 4.76% and increased OEE from 79.58% to 87%. The results establish fixture mechanics as a primary control variable for weld robustness and provide a physically grounded framework for predictive quality optimization in robotic CMT systems.