**3.2 Material properties**

Table 3 lists the room temperature material properties used for nickel, YSZ and LSM (Johnson & Qu, 2008; Anandakumar et al., 2010).


Table 3. Room temperature material properties used in FE analyses

Continuum Mechanics of Solid Oxide Fuel Cells

not change over the temperature range considered.

Fig. 6. Stress-plastic strain curve for nickel (Ebrahimi et al., 1999).

**4. Finite element analysis results and discussion** 

**4.1 Stress analysis** 

elements and 395,131 nodes.

**4.1.1 Anode microstructure** 

N/m2 (i.e., Pa).

Using Three-Dimensional Reconstructed Microstructures 79

Figure 6 shows the stress-strain curve used to describe the elastic-plastic behavior of nickel (Ebrahimi et al., 1999). It was assumed in this work that the stress-strain curve of nickel does

The full 3-D FE models of the anode (50:50 NiO:YSZ weight percentage composition) and cathode (50:50 LSM:YSZ weight percentage composition) are shown in Figure 7. The FE anode model consists of 406,465 elements and 473,181 nodes. The cathode model has 244,584

The von Mises stress contour plots for the anode at ΔT = 100⁰C, 500⁰C, and 800⁰C are shown considering elastic-plastic behavior of nickel in Figure 8. The stress values are in units of

Fig. 7. Three-dimensional FE models of anode (left) and cathode (right)

Figure 4 shows the variation of the coefficients of thermal expansion of nickel and YSZ with temperature (Johnson & Qu, 2008). The CTE of LSM was assumed to be constant over the temperature range considered. The room temperature value of the CTE of LSM (as shown in Table 3) was used in the FE analyses of the cathode.

Fig. 4. Variation of CTE of nickel and YSZ with temperature (Johnson & Qu, 2008).

Figure 5 shows the variation of the Young's modulus of LSM and YSZ with temperature (Giraud & Canel, 2008). The Young's modulus of nickel was assumed to be constant over the temperature range considered. The room temperature value of the Young's modulus of nickel (as shown in Table 3) was used in the FE analyses of the anode.

Fig. 5. Variation of Young's modulus of LSM and YSZ with temperature (Giraud and Canel, 2008).

Figure 4 shows the variation of the coefficients of thermal expansion of nickel and YSZ with temperature (Johnson & Qu, 2008). The CTE of LSM was assumed to be constant over the temperature range considered. The room temperature value of the CTE of LSM (as shown in

Fig. 4. Variation of CTE of nickel and YSZ with temperature (Johnson & Qu, 2008).

nickel (as shown in Table 3) was used in the FE analyses of the anode.

2008).

Figure 5 shows the variation of the Young's modulus of LSM and YSZ with temperature (Giraud & Canel, 2008). The Young's modulus of nickel was assumed to be constant over the temperature range considered. The room temperature value of the Young's modulus of

Fig. 5. Variation of Young's modulus of LSM and YSZ with temperature (Giraud and Canel,

Table 3) was used in the FE analyses of the cathode.

Figure 6 shows the stress-strain curve used to describe the elastic-plastic behavior of nickel (Ebrahimi et al., 1999). It was assumed in this work that the stress-strain curve of nickel does not change over the temperature range considered.

Fig. 6. Stress-plastic strain curve for nickel (Ebrahimi et al., 1999).
