Fiber Dependent Injection Molding Simulation Of Discontinuous Reinforced Polymers

This work presents novel simulation techniques for injection molding of fiber reinforced polymers. These include approaches for anisotropic flow modeling, hydrodynamic forces from fluid on fibers, contact forces between fibers, a novel fiber breakage modeling approach and anisotropic warpage analysis. Due to the coupling of fiber breakage and anisotropic flow modeling, the fiber breakage directly influences the modeled cavity pressure, which is validated with experimental data.

Discontinuous long fiber reinforced polymer structures with local continuous fiber reinforcements represent an important class of lightweight materials with broad design possibilities and diverse technical applications, e.g. in vehicle construction. However, in contrast to continuous fiber reinforced composites, extensively used in the aircraft industry, there is still a lack of integrated and experimentally proven concepts for manufacture, modeling, and dimensioning of combinations of discontinuously and continuously reinforced polymer structures. This is partly ascribed to the complexity of the manufacturing processes of discontinuously reinforced polymers, with heterogeneous, anisotropic, and nonlinear material and structural properties, but also to the resulting bonding problem of both material types. This book addresses these issues, including both continuous and discontinuous fiber processing strategies. Specific design strategies for advanced composite reinforcement strategies are provided, with an integrated and holistic approach taken for composites material selection, product design, and mechanical properties. Characterization, simulation, technology, design, future research, and implementation directions are also included. Especially in the field of application of three-dimensional load-bearing structures, this book provides an excellent foundation for the enhancement of scientific methods and the education of engineers who need an interdisciplinary understanding of process and material techniques, as well as simulation and product development methods.

This work describes a method for weighted least squares approximation of an unbounded number of data points using a B-spline function. The method can shift the bounded B-spline function definition range during run-time. The approximation method is used for optimizing velocity trajectories for an electric vehicle with respect to travel time, comfort and energy consumption. The trajectory optimization method is extended to a driver assistance system for automated vehicle longitudinal control.

With the further development of automated driving, the functional performance increases resulting in the need for new and comprehensive testing concepts. This doctoral work aims to enable the transition from quantitative mileage to qualitative test coverage by aggregating the results of both knowledge-based and data-driven test platforms. The validity of the test domain can be extended cost-effectively throughout the software development process to achieve meaningful test termination criteria.

Discontinuous fiber-reinforced polymers have gained importance in transportation industries due to their outstanding material properties, lower manufacturing costs and superior lightweight characteristics. One of the most attractive attributes of discontinuous fiber-reinforced composites is the ease with which they can be manufactured in large numbers, using injection and compression molding processes. The main aim of this Special Issue is to collect various investigations focused on the processing of discontinuous fiber-reinforced composites and the effect that processing has on fiber orientation, fiber length and fiber density distributions throughout the final product. Papers presenting investigations on the effect that fiber configurations have on the mechanical properties of the final composite products and materials were welcome in the Special Issue. Researchers who model and simulate processes involving discontinuous fiber composites as well as those performing experimental studies involving these composites were welcomed to submit papers. The authors were encouraged to present new models, constitutive laws, and measuring and monitoring techniques to provide a complete framework on these groundbreaking materials and to facilitate their use in different engineering applications.

This book is a printed edition of the Special Issue "Discontinuous Fiber Composites" that was published in J. Compos. Sci.

There are many books on composite material analysis, but most cover mainly continuous fiber materials, rather than those filled with discontinuous fibers, which are particularly attractive for large-volume and low-cost applications. This book provides the theoretical and practical background to design and use discontinuous fiber-reinforced polymer materials, with an emphasis on structural parts for the automotive industry. Moreover, the product of years of collaborative work between industry and academia is presented in an easy-to-use, comprehensive manner. The information provided makes it possible for someone with an engineering background to understand the micromechanics of discontinuous fiber-reinforced materials and, hence, analyze the structural performance of components designed with such materials. The book employs a practical approach to cover the key, unique capabilities that are critical for a successful structural analysis of discontinuous fiber-reinforced polymer structures: -Process simulation to estimate the condition of fibers in the finished parts, i.e., fiber length, orientation, and concentration -Capability to measure micro structure, i.e., fiber length distribution, fiber orientation tensors, and fiber concentration, etc. -Estimation of material properties in the part based on fiber condition, as well as environmental conditions such as temperature A broad range of areas is included, such as joining and assembly.

Ihrer Arbeit in der Originalsprache: This work aims at identifying relevant road surface characteristics to mitigate tire-road noise of free-rolling tires using a systematic approach. As using open porous roads is already known as an efficient measure to reduce tire rolling noise, this study will focus on compact road surfaces which have a low acoustic absorption. Measurements on standardized ISO 10844 test tracks and on public roads are used to study the norm's representativity and its completeness.