Evaluation of potential for metal/polymer/metal sandwich material as outer panels for trucks

Sammanfattning: Reducing the weight of the truck vehicle conveys more cargo to be carried by thetrailer. This has a significant impact on the efficiency of the transport lowering both the total cost of cargo moved and the total carbon dioxide emitted. Half of the body in-white weight of a truck is comprised out of panels made out of thin mild forming steel which cannot be made thinner to reduce weight due to the lowered stiffness it would entail. Sandwich materials have a high stiffness to weight ratio and would for the same panel thickness as regular forming steel have a comparable bending stiffness but lowered weight. This master thesis is intended to be a preliminary study for Scania CV AB on sandwich materials and its potential use as lightweight panels in their trucks. With the intention of investigating whether a commercial sandwich material is capable of filling the role as outer panels of a truck, comparative tests regarding significant matters such as forming and painting was made on identically manufactured demonstrators comparing a sandwich material and a regular forming steel material. The tests identified weaknesses in the current manufacturing process for parts of a sandwich material. Such limitations are problems with painting and joining due to isolated cover sheets, forming problems revealing sink marks likely due to different spring back of the material and hemming flaws due to inadequately optimized hemming technique and anisotropy. Now that more knowledge of sandwich materials has been gained, counter measures for these findings can be made in order to take another step towards lowering the weight of the truck and a more efficient way of transporting goods.