TY - BOOK

T1 - Pultrusion of thermoset based profiles-state of the art regarding materials, process set-ups, process modeling, and process simulation

AU - Costa Dias, Rita de Cassia

N1 - no embargo

PY - 2020

Y1 - 2020

N2 - This thesis focuses on mathematical modeling of the pultrusion process in order to improve the degree of cure and thermal arrangement during the polymerization reaction. The main focus is on the use of thermo-chemical and empirical kinetic models for the prediction of the degree of cure. While empirical kinetic models are easy to handle, they are limited in terms of providing it with an understanding of the system due to the absence of knowledge regarding the full kinetic of the functional groups. In this regard, the use of phenomenological models, based on material scales of functional groups involved in the curing reaction, is a noteworthy strategy. The kinetic parameters of both models were estimated from differential scanning calorimetry (DSC) experiments of an epoxy resin. Results of parameter estimation, by comparison with experimental data, revealed that the kinetic models could be reasonably adjusted to the experimental cure behavior, presenting a small mean squared deviation. In the pultrusion process, there are many amount of variables involved and this includes the pull speed and die temperature. Thus, the dedication to the study of computational models is required in order to analyze the process for different composite manufacturing aspects such as heat transfer, curing properties in order to obtain good quality over the mechanical properties of the pultruded material. In addition to the scientific and thermochemical models developed in this thesis, we observed that few studies have been focusing on matrix temperature optimization of the pultrusion process. This work also aims to optimize the die-temperature of pultrusion based on minimizing the objective function by varying the values of the temperatures of die heaters, which are the decision variables of optimization problem. This work show the mean of the cure degree is satisfactory when used with many internal heaters and the results indicate that the algorithm used in this study is numerically reliable and provides optimal die temperatures for providing uniformly cured material.

AB - This thesis focuses on mathematical modeling of the pultrusion process in order to improve the degree of cure and thermal arrangement during the polymerization reaction. The main focus is on the use of thermo-chemical and empirical kinetic models for the prediction of the degree of cure. While empirical kinetic models are easy to handle, they are limited in terms of providing it with an understanding of the system due to the absence of knowledge regarding the full kinetic of the functional groups. In this regard, the use of phenomenological models, based on material scales of functional groups involved in the curing reaction, is a noteworthy strategy. The kinetic parameters of both models were estimated from differential scanning calorimetry (DSC) experiments of an epoxy resin. Results of parameter estimation, by comparison with experimental data, revealed that the kinetic models could be reasonably adjusted to the experimental cure behavior, presenting a small mean squared deviation. In the pultrusion process, there are many amount of variables involved and this includes the pull speed and die temperature. Thus, the dedication to the study of computational models is required in order to analyze the process for different composite manufacturing aspects such as heat transfer, curing properties in order to obtain good quality over the mechanical properties of the pultruded material. In addition to the scientific and thermochemical models developed in this thesis, we observed that few studies have been focusing on matrix temperature optimization of the pultrusion process. This work also aims to optimize the die-temperature of pultrusion based on minimizing the objective function by varying the values of the temperatures of die heaters, which are the decision variables of optimization problem. This work show the mean of the cure degree is satisfactory when used with many internal heaters and the results indicate that the algorithm used in this study is numerically reliable and provides optimal die temperatures for providing uniformly cured material.

KW - Heilungsverhalten

KW - Thermische Analyse

KW - Wärmehärtbare Harze

KW - Pultrusion

KW - Simulation

KW - Optimierung

KW - Cure behavior

KW - Thermal Analysis

KW - Thermosetting resins

KW - Pultrusion

KW - Simulation

KW - Optimization

M3 - Doctoral Thesis

ER -