Reliability-Based Design Optimization for Crane Metallic Structure Using ACO and AFOSM Based on China Standards

Abstract

The design optimization of crane metallic structures is of great significance in reducing their weight and cost. Although it is known that uncertainties in the loads, geometry, dimensions, and materials of crane metallic structures are inherent and inevitable and that deterministic structural optimization can lead to an unreliable structure in practical applications, little amount of research on these factors has been reported. This paper considers a sensitivity analysis of uncertain variables and constructs a reliability-based design optimization model of an overhead traveling crane metallic structure. An advanced first-order second-moment method is used to calculate the reliability indices of probabilistic constraints at each design point. An effective ant colony optimization with a mutation local search is developed to achieve the global optimal solution. By applying our reliability-based design optimization to a realistic crane structure, we demonstrate that, compared with the practical design and the deterministic design optimization, the proposed method could find the lighter structure weight while satisfying the deterministic and probabilistic stress, deflection, and stiffness constraints and is therefore both feasible and effective.

Failure probability analysis of overhead crane bridge girders within uncertain design parameters

“…where f x (X) is the probability density function of X and I(X) is the indicator function defined as, I(X) = 1 if X is in the failure region e.g., G (X) < 0 0 otherwise (15) Eq. (13) shows that the failure probability is indeed the mean value of the indicator function I(X), which can thus be estimated as,…”

“…Deterministic optimum designs, which are pushed to the limits of their constraint boundaries and have no room for uncertainty, may result in low-reliability designs [13,14]. Recently, reliability-based design problems of crane structure have been reported in a few reference works [15]. Using the FEM simulations and response surface method (RSM), a reliability-based design of the structure of tower crane was introduced in Ref.…”

Probability Analysis of Crane Load and Load Combination Actions

“…As a tool of moving and transporting material, cranes are used in various fields to handle heavy objects [6]. Generally, when the crane structure is engaged in regular heavy work, there is a small observation interval Δ in which all possible crane operating conditions within a complete operating period can be observed.…”

“…In Figure 4, the distribution of the arbitrary point-in-time value is plotted in (2) and 3with the statistical parameters listed in Table 1 (the black line). The distribution of the maximum value during the design reference period = 50 years is plotted using (5) and (6) with the maximum value method (the red line, using the stationary binomial random process) and (16) with the POT method (the blue line, using the Poisson rectangular wave process). The maximum value is larger than the arbitrary point-in-time value for the same guarantee rate.…”

“…But crane load is much different with other live loads when using the model code. In industry building, crane load and their combination actions are functions of both time and space [6]. The time variable shows the different crane load values in different points in time.…”