FEA simulations to predict the mechanical resistance of injection weld lines on a vehicle radiator plastic water tank 2005-01-4123
Vehicle radiators water tanks must withstand high pressure and temperature loads when in use. In most applications, they are made out of plastic material, usually Polyamide 66, filled with glass fiber to increase the stiffness, and molded by injection. However, in many cases, their geometry complexity can not prevent different plastic material flow fronts from meeting in different regions during the mold cavity filling process, hence creating weld lines. Since regions presenting weld lines tend to have weaker mechanical resistance, their precise location become of primary interest and require more attention, so that their response to the mechanical stress resulting from the radiator normal load conditions can be studied.
In such cases, in order to optimize the product development process, to avoid early failures about the weld lines regions and to reduce the final validation time, computational simulation tools are used during the product concept and design phase.
This paper presents a two step process: First, the user predicts the location of the weld lines by using a plastic injection simulation package. Once their locations are known, weld line resistance, previously validated through radiator experimental tests, is used as an input for a structural FEA package.
Finally, results obtained using this method are presented and compared to stress-strain curves values derived from special tensile samples.