# OS-E: 8000 3-Point Bending of Phone

In this example, 3-point bending analysis of a phone is performed to check the flexural strength of the phone.

The objective is to analyze the stresses and displacement of the phone when it is pressed by pressing cylinder from top and constrained by the fixed cylinder at the bottom.

## Model Files

Refer to Access the Model Files to download the required model file(s).

The model file used in this example includes:

3point_bending_of_Phone.fem

## Model Description

The phone containing all the parts inside is subjected to bending using pressing cylinder. The phone parts are given appropriate contacts and material. The 3-point bending analysis of the phone is performed using RBODY. The lower cylinders are fixed, the phone is resting on it and the pressing cylinder is given displacement of 8 mm.
 PCB Material Properties Young's modulus 15000 $\left[\mathrm{MPa}\right]$ Poisson's ratio 0.3 Density 3e-9 $\left[\frac{\text{k}\text{g}}{\text{m}{\text{m}}^{3}}\right]$ Battery Material Properties Young's modulus 2000 $\left[\mathrm{MPa}\right]$ Poisson's ratio 0.3 Density 2.5e-09 $\left[\frac{\text{k}\text{g}}{\text{m}{\text{m}}^{3}}\right]$ PCB Comps Young's modulus 2000 $\left[\mathrm{MPa}\right]$ Poisson's ratio 0.3 Density 2.e-09 $\left[\frac{\text{k}\text{g}}{\text{m}{\text{m}}^{3}}\right]$
Bolt and carrier plate
Steel nonlinear material
Frame, button and front back cover (polymer plastic)
Young's modulus
2000 $\left[\mathrm{MPa}\right]$
Poisson's ratio
0.4
Density
1.1e-9 $\left[\frac{\text{k}\text{g}}{\text{m}{\text{m}}^{3}}\right]$
Table 1. Stress Strain Plot Values
Strain Stress
0 50
0.01 55
0.1 60
0.3 65
Glass
Young's modulus
70000 $\left[\mathrm{MPa}\right]$
Poisson's ratio
0.3
Density
2.5e-9 $\left[\frac{\text{k}\text{g}}{\text{m}{\text{m}}^{3}}\right]$
Carrier plastic (glass fiber plastic)
Young's modulus
10000 $\left[\mathrm{MPa}\right]$
Poisson's ratio
0.4
Density
1.4e-9 $\left[\frac{\text{k}\text{g}}{\text{m}{\text{m}}^{3}}\right]$
Table 2. Stress Strain Plot Values
Strain Stress
0 100
0.01 120
0.054 140
With a stress of 587 $\left[\mathrm{MPa}\right]$ on the glass of the phone indicates that glass will break at the location (Figure 3).