In power and energy systems, both the aerodynamic performance and the structure reliability of turbine equipment are affected by utilized blades. In general, the design process of blade is high dimensional and nonlinear. Different coupled disciplines are also involved during this process. Moreover, unavoidable uncertainties are transported and accumulated between these coupled disciplines, which may cause turbine equipment to be unsafe. In this study, a saddlepoint approximation reliability analysis method is introduced and combined with collaborative optimization method to address the above challenge. During the above reliability analysis and design optimization process, surrogate models are utilized to alleviate the computational burden for uncertainties‐based multidisciplinary design and optimization problems. Smooth response surfaces of the performance of turbine blades are constructed instead of expensively time‐consuming simulations. A turbine blade design problem is solved here to validate the effectiveness and show the utilization of the given approach.

In practical engineering, the choice of blade shape is crucial in the design process of turbine. It is because not only the structural stability but also the aerodynamic performance of turbine depends on the shape of blades. Generally, the design of blades is a typical multidisciplinary design optimization problem which includes many different disciplines. In this study, a fluid-structure coupling analysis approach is proposed to show the application of multidisciplinary design optimization in engineering. Furthermore, a strategy of uncertainty-based multidisciplinary design optimization using fluidstructure coupling analysis is proposed to enhance the reliability and safety of blades in turbine. The design of experiment technique is also introduced to construct response surface during uncertainty-based multidisciplinary design optimization using fluid-structure coupling analysis. The design solution shows that the adiabatic efficiency is increased and the equivalent stress is decreased, which means that better performance of the turbine can be obtained.

The basic function of hoop connection is to connect two parts of unmanned undersea vehicle (UUV) shell. The hoop connection of UUV is presently designed via the static strength method which might result in more redundancy than that being required. However, uncertainties are ubiquitous in any stage of the UUV development. A design optimization method is proposed in this paper by combining the Finite Element Method (FEM), Response Surface Methodology (RSM) and First Order Reliability Method (FORM) to facilitate the design of hoop connection under uncertainty. Meanwhile, the effectiveness of the proposed method is testified by an engineering example.

Uncertainties exist widely in the time-dependent performance degeneration processes of engineering systems in practice. Generally, in order to simplify the calculation, the random processes of uncertainty information are usually treated as time-independent or monotonic processes. The corresponding uncertainty analysis approaches are time independent. However, in this situation, the failure probabilities of performance can only be considered at the end of structure lifetime. To deal with the above challenge, an enhanced outcrossing rate method using the Kriging interpolation method is proposed in this study. The proposed method can utilize the correlation information between two design variables to predict the stress level and describe the time-dependent degeneration process. An uncertainty-based design and optimization problem of machine tool spindle is utilized to illustrate the effectiveness of the proposed strategy.

In remotely operated vehicle (ROV), worm gearing is usually used to transfer movement and power between two staggered axes. In the design process of worm gearing, complex gear face and the exist of uncertainty make its design and modeling so difficult will affect its reliability. In this paper, a reliability-based design (RBD) method is proposed for worm gearing of remotely operated vehicle under two types uncertainties, and the first-order reliability method (FORM) is used to calculate the reliability of worm gearing. Finally, an engineering example is used to illustrate the effectiveness of the reliability design method for worm gearing of remotely operated vehicle.