## 4 Discussion  
According to LCA, the geometric design of various components can significantly influence the optimization of each of the following product properties: the environmental impacts, production cost, safety, and mechanical properties. In addition, it is very important in the simultaneous optimization of multiple product properties. The results of this study suggest that the optimization of multiple product properties is more complicated than that of individual product properties, especially when the goals are contradictory. For the geometric design of LCD display frames, although a lightweight design requires fewer raw materials and a lower production cost, along with bringing about smaller environmental impacts, there will be safety concerns. This agrees well with the literature [21]. To strike a balance between different product properties, a Pareto set can be adopted to obtain the optimal solutions for different design parameters and their corresponding weights. Undoubtedly, another direct way is to select other materials to resolve the safety issues. However, materials with better mechanical performances may lead to more adverse environmental impacts. This was revealed by the study by [PERSON] et al. [17] on common beverage packaging materials. Hence, a multi-disciplinary and multi-objective design optimization exploring the effects of the geometry and materials of different components on the environmental impacts and safety of a product must seek the solution that gives the maximum overall benefit. In this research, a Pareto set was used to optimize LCD display frames. It was discovered that a compromise had to be made in the material selection. Although PC is mechanically stronger than ABS, the overall performance of the frame was \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Method**} & \multirow{2}{*}{\(W_{1}\)} & \multirow{2}{*}{\(W_{2}\)} & \multirow{2}{*}{\(G_{1}\)} & \multirow{2}{*}{\(G_{2}\)} & \multicolumn{2}{c}{**Objective**} & \multirow{2}{*}{\(X_{1}\) (mm)} & \multirow{2}{*}{\(X_{2}\) (mm)} & \multirow{2}{*}{\(X_{3}\)} & \multicolumn{2}{c}{**Environmental**} & \multirow{2}{*}{\(W_{1}\), weight of the environmental impact function \(V_{1}(X);W_{2}\), weight of the von Mises stress function \(V_{2}(X);G_{1}\), function value of \(V_{1}(X)\) after GA calculation; \(G_{2}\), function value of \(V_{2}(X)\) after GA calculation. \\ \hline
2 & 0.55 & 0.45 & 0.217 & 0.076 & 0.293 & 0.368 & 0.200 & 1 & 1.5076 & 1.9849 \(\times 10^{5}\) \\ \hline
2 & 0.65 & 0.35 & 0.167 & 0.132 & 0.299 & 0.310 & 0.200 & 1 & 1.3493 & 2.5658 \(\times 10^{5}\) \\ \hline
2 & 0.7 & 0.3 & 0.105 & 0.179 & 0.284 & 0.265 & 0.200 & 1 & 1.2261 & 3.1807 \(\times 10^{5}\) \\ \hline
2 & 0.75 & 0.25 & 0.01 & 0.239 & 0.249 & 0.206 & 0.200 & 1 & 1.0642 & 4.2043 \(\times 10^{5}\) \\ \hline \hline \end{tabular}  
* Notation: \(X_{1}\), display surface thickness; \(X_{2}\), outer layer thickness; \(X_{3}\), material; \(W_{1}\), weight of the environmental impact function \(V_{1}(X);W_{2}\), weight of the von Mises stress function \(V_{2}(X);G_{1}\), function value of \(V_{1}(X)\) after GA calculation; \(G_{2}\), function value of \(V_{2}(X)\) after GA calculation.  
\end{table} 
Table 4: Multi-disciplinary and multi-objective optimization results based on Method 1 and Method 2.  
better when ABS was used. Similar findings have also been noted in the literature [26]. Moreover, the RSM could be applied at the design stage to determine the key factors affecting the environmental impacts and mechanical strength of an LCD display frame. This method also reflects the relationship between these key factors and the product quality. This enables engineers to quickly obtain the corresponding environmental impacts and von Mises stresses after modifying the geometric dimensions. [PERSON] et al. [21] adopted this approach to realize the eco-design of Halbach magnetic rollers.