Design of Selectively Compliant Morphing Structures with Shape-Induced Bi-stable Elements

Design, Manufacture and Wind Tunnel Test of a Modular FishBAC Wing with Novel 3D Printed Skins

“…Advancements in smart materials and lightweight structures, which have led to lighter and less complex morphing mechanisms. For example, developments in piezoelectric materials [5,6] and Shape-Memory Alloys (SMA) [7,8] have focused on exploring alternative actuation mechanisms, whereas the further understanding of composite laminates has led to exploiting structural instabilities for shape changing [9][10][11]. Furthermore, some concepts achieved variable camber by embedding actuators within the wing skin [5,12], whereas others focused on active actuation of the internal load-bearing structural members [8,[13][14][15].…”

Passive load alleviation on wind turbine blades from aeroelastically driven selectively compliant morphing

“…It must be stressed that these values do not fall in the range of velocities, as presented in Table 2. This is because the design space (bistable element, aerofoil skin material, and chord length) is limited to allow for manufacturability of the concept with conventional composite prepregs; however, the utilization of thin-ply technologies 54 or element geometry for achieving bistability 26,27,29 can allow for designs within the mentioned range. Indeed, the obtained relative differences between the morphing velocities are significant even outside the noted optimal operational interval.…”

“…We refer to compliance selectivity as the capacity for structures to alter their stiffness as a function of time, in contrast to structures with spatially distributed reinforcements that show time‐invariant, spatially varying modulus 19 . The type of selective compliance we explore in this paper can be achieved, for example, using mechanistic approaches, 20,21 by pressurized composites, 22,23 or bistable beam‐like elements inside truss‐like compliant systems 24‐28 . Structures displaying such selectively compliant behavior leverage geometric effects that are independent of the constitutive material used 29 .…”

“…19 The type of selective compliance we explore in this paper can be achieved, for example, using mechanistic approaches, 20,21 by pressurized composites, 22,23 or bistable beam-like elements inside truss-like compliant systems. [24][25][26][27][28] Structures displaying such selectively compliant behavior leverage geometric effects that are independent of the constitutive material used. 29 Phase transitions found in shape memory alloys 30,31 or thermoplastic polymers 32,33 have been used to achieve variable stiffness; however, the use of specific constitutive compounds restricts the choice of materials from which the desired stiffness adaptation can be attained.…”

Numerically Efficient Three-Dimensional Fluid-Structure Interaction Analysis for Composite Camber Morphing Aerostructures

“…This has been partly due to new developments in smart materials and lightweight structures and advancements in structural modeling, which have allowed researchers to develop new morphing concepts [7]. For example, developments in piezoelectric materials [8,9] and Shape-Memory Alloys (SMA) [10,11] have focused on exploring alternative actuation mechanisms, whereas further understanding of composite laminates have led to exploiting structural instabilities for shape changing [12][13][14]. However, most of these research efforts have essentially focused on 2-D morphing airfoils, and not necessarily on their integration into three-dimensional wings-from a systems level point-of-view, and the potential benefits and complications this may bring.…”