A simulation model is presented in this work, capable to predict temperature and velocity of the extrudate as well as the compressive force acting on the filament in a fused filament fabrication (FFF) machine operating with a Bowden extruder. The simulation model is developed for future incorporation into a larger on-machine apparatus designed for process monitoring and adaptive control and destined to the fabrication of high value-added parts. The simulation model captures mechanical aspects of the extruder (including slippage at the drive gear, filament compression into the hot end), as well as temperature and pressure changes within the extrusion chamber, where the filament is liquefied and transformed into the extrudate. The model is implemented so that it can react to changes in the part program as it is being executed, offering predictions on the extrusion process that can be compared with sensor measurements. The simulation model is implemented in prototype form and calibrated on a multi-sensor FFF machine working with a PLA filament within a range of predefined operating conditions (heating temperatures and print feed rates). Load cells, high-speed optical imaging and infra-red thermal imaging of the extrudate mounted on the FFF machine are used to verify the predictions of the simulation model.

在这项工作中提出了一个仿真模型，该模型能够预测挤出物的温度和速度，以及在使用Bowden挤出机的熔融长丝制造（FFF）机器中作用于长丝的压缩力。该仿真模型是为将来集成到用于过程监控和自适应控制而设计的大型机上设备而开发的，旨在用于制造高附加值的零件。仿真模型捕获了挤出机的机械方面（包括驱动齿轮的打滑，长丝进入热端的压缩）以及挤出室内的温度和压力变化，在那里长丝被液化并转化为挤出物。该模型的实现使得它可以在执行零件程序时对零件程序中的更改做出反应，提供可与传感器测量结果相比较的挤压过程预测。仿真模型以原型形式实现，并在多传感器FFF机器上进行校准，该机器在预定的工作条件（加热温度和打印进给速度）范围内与PLA灯丝一起工作。FFF机器上安装的挤出物的称重传感器，高速光学成像和红外热成像用于验证仿真模型的预测。