Development of a structural optimization strategy for the design of next generation large thermoplastic wind turbine blades

Abstract

This paper presents the development of a structural optimization process for the design of future large thermoplastic wind turbine blades. The optimization process proposed in this paper consists of three optimization steps. The first step is a topology optimization of a short untwisted and non tapered section of the blade, with the inner volume used as the design domain. The second step is again a topology optimization, but on the first half of a blade to study the effect of non symmetry of the structure due to blade twist and taper. Results of this optimization step are then interpreted to build a shell model of the complete blade structure to perform composite size optimization based on a minimum mass objective subjected to constraints on deflection, composite strength and structural stability. Different blade models using ribs are then optimized and compared against conventional blade structure (box spar structure without ribs and single web structure without ribs).The use of ribs in wind turbine blade structures, which is more adapted to thermoplastic composite manufacturing than for thermoset composites, leads to slightly lighter blades than conventional blade structures.

Load application method for shell finite element model of wind turbine blade

“…In the first group (Figure 2(a)), load resultants are applied directly to a small number of sections of the blade, either through a master node which controls the whole section displacement by relations between nodes degrees of freedom (Forcier and Joncas, 2011; Haselbach et al, 2016; Joncas, 2010) or directly onto one (Griffith and Ashwill, 2011; Shokrieh and Rafiee, 2006) or a small number (Lindgaard and Lund, 2010; Lund and Stegmann, 2005) of nodes of the section of the shell FEM. This group consists of approaches where load resultant is applied at the blade tip or at the end of the studied segment (Haselbach et al, 2016; Lindgaard and Lund, 2010; Lund and Stegmann, 2005), and approaches where loads computed at different sections of the blade are applied onto the section where they had been computed (Griffith and Ashwill, 2011; Li et al, 2013; Shokrieh and Rafiee, 2006).…”

Multidisciplinary dynamic optimization of horizontal axis wind turbine design

“…These aeroelastic effects are further coupled with generator dynamics and control system effects. Several recent studies have utilized MDO for wind turbine design (Zakhama and Abdalla 2010;Forcier and Joncas 2012). For example, Ashuri et al (2014) optimized the rotor and tower simultaneously, including satisfaction of relevant aerodynamic and structural constraints.…”

Optimization Method for Girder of Wind Turbine Blade

“…Blade design is here performed with a constrained optimization-based procedure. In formulating an optimization problem, three principal phases must be considered [9,10]: The blade profile structure is shown in Figure 1, given girder location and width parameters, and it defines the ratio which distance that from shear web of before the main girder to front end divides section length is , section width of main girder and section chord ratio is .…”