Image made using the COMSOL Multiphysics® software.
Analysis of a Wind Turbine Composite Blade.
Composite Materials Module is designed to assist you in modeling structural behavior that includes layered shells. The module is designed for researchers, engineers, teachers, and students who want to simulate the behavior of layered structures. Using the Composite Materials Module, a laminated composite shell, also known as composite laminate, can be modeled. A composite laminate is an assembly of layers with different mechanical properties. The laminate is designed to provide required in-plane stiffness, bending stiffness, shear stiffness, coefficient of thermal expansion, and so on. Different materials can be used in different layers, producing a hybrid laminate. In general, the individual layers are orthotropic or transversely isotropic, making the laminate anisotropic. Multiscale analysis of a composite laminate can be performed using micromechanical and macromechanical modeling approaches. A micromechanical analysis considers an individual constituents in a material subvolume. The aim is to compute the homogenized material properties of a single layer. In contrast, a macromechanical analysis considers an entire laminate that consists of many layers. The aim is to compute the macroscopic response of a laminate under various loading conditions.
In COMSOL Multiphysics, composite laminates are analyzed either using Layerwise 3D Elasticity theory through the Layered Shell interface or using First Order Shear Deformation theory (ESL-FSDT) theory through one of the Linear Elastic Material, Layered, Hyperelastic Material, Layered, or Piezoelectric Material, Layered material models in the Shell interface. Very thin laminates, of essentially zero bending stiffness, are analyzed using an equivalent single layer theory using the Linear Elastic Material, Layered material model in the Membrane interface.
Wind turbines are an increasingly popular source of renewable energy. As such, the design, analysis and manufacture of wind turbines are important to the energy industry. The turbine blades are critical components of a wind turbine. When generating electric power through rotation, they have to withstand different types of loads, such as wind, gravitational, and centrifugal loads. The sheer size of a blade necessitates light and strong materials, and composites are well suited for this.
This example shows how to analyze a composite wind turbine blade using a mixture of carbon–epoxy, glass–vinylester and PVC foam. The blade is constructed as a sandwich structure where the PVC foam core is sandwiched between carbon–epoxy and glass–vinylester.
This tutorial is intended as a simple example showing how to model piezoelectric devices using the layered shell functionality.
Two cases of material orientation are investigated. In the first case, the pole axis is normal to the shell surface, which results in a change in thickness of the deformed shell. In the second case, the pole axis is tangential to the shell, which leads to the shell bending.
Composite materials are often used in structural applications, where the ability to tailor properties such as stiffness and strength make them attractive compared to traditional engineering materials. In addition to structural applications, composites are also used in applications where both thermal and structural properties are important. An example is silicon wafers used in the electronics industry. Consequently, coupled thermal-structural analyses of thin structures is becoming increasingly important from a simulation standpoint.
In this example, a laminated composite shell subjected to a deposited beam power heat source is analyzed from thermal and structural points of view. The layerwise theory based approach is used to model the structural part of the shell. The effect of the position of a heat source on the stress and deformation profiles is studied.
Layered shell elements, which are used for modeling composite shells, often connected to solid and shell elements in cladding or side-by-side configuration to represent a realistic structure. For such applications, it becomes important to connect layered shell element correctly and easily with other structural elements.
In this tutorial and verification problem, you will learn how to connect layered shell elements to solid and shell elements in different configurations. The results are also compared to a solid model of the same geometry.
In this example, the structural integrity of a cylinder made by a fiber composite is assessed both at the macroscale and at the microscale level. Along with macroscale analyses, structural composites need microscale stress and failure analyses to identify the critical constituents in laminate structures.
Fiber composites are widely used in industrial applications. Compared to more traditional metallic engineering materials, fiber composites often have superior specific stiffness and strength properties, and they are often more corrosion resistant. Also, properties like strength, stiffness, and toughness can often be tailored to specific applications. A fiber composite consists of load carrying fibers embedded in a polymer resin. The composite material is typically a laminate of individual layers, where the fibers in each layer are unidirectional. This model demonstrates how to perform a stress analysis of a laminated composite cylinder.
Modeling individual fibers in every layer in the laminate is unfeasible. A simplified micromechanics model of a single carbon fiber in epoxy is instead used to estimate the homogenized elastic properties of a single layer. These properties are then used in the macromechanical model of the laminated composite cylinder. Two approaches are used to model the laminate, namely the Layerwise (LW) theory and the Equivalent Single Layer (ESL) theory.
Delamination or the separation of layers is a common failure mode in laminated composite materials. Various factors, including loading, defects in the material, and environmental conditions can trigger the initiation and propagation of layer separation. This leads to degraded structural performance and sometimes even complete failure of the structure.
This example considers the response of a delaminated plate under forced vibration. The composite plate is analyzed for two different locations of delamination and compared with the intact plate, without delamination. The plate is made of three layers with [90/45/0] stacking. The delamination is assumed to occur in a circular or semi-circular region between the second and third layers of the laminate and modeled using the layerwise theory.
