Wire-Mesh Products Inc.

Finite Element Analysis continued

pages 1 2 3 4 5

RESULTS

Series 1 Results

Small and large deflection analyses were conducted, however, no significant differences were found. Table II contains a summary of the results from this series. The results in the table show that the flattened wire spiral had a 25% higher stress level and elongated 30% more than the round spiral wire.

Series 2 Results

The normal stress (sx) and the spiral elongation results from this series (Table III) are within 6% and 9%, respectively, of the results from Series 1. The spiral elongation was considered to be twice the displacement of the node located at the top center of the spiral loop. the elongation of the flattened wire spiral was 27% greater than the round wire spiral. In this series, there was no significant difference in the normal stress; however, the von Mises stress for the flattened wire was 44% higher than the round wire.

Table II Series 1 Baseline Results		Table III Series 2 Solid Model with Linear Material and Pressure Loading

Table IV Series 3 Model Contact Interface Results		Table V Overall Furnace Belt Behavior

Series 3 Results

The maximum von Mises stress and the elongation caused by the spiral and connecting wire interface are shown in Table IV. It can be seen that there are significant differences in elongation and stress between the two configurations. Figs. 10a and 10b show contour plots of stresses for the two configurations. When compared to the round spiral, the corner of the flattened spiral digs into the spiral resulting in a large displacement and a stress 43% increase in stress.


Fig. 10a Von Mises stress of (a) round spiral loaded connecting rod and (b) flattened spiral loaded connecting rod.

Overall Furnace Belt Elongation

The overall furnace belt elongation can be obtained by combining the results from Series 2 and 3. Table V shows initial elongation of a belt made with round and flattened spirals to be 1.09 x 10-2 in./ft. and 2.96 x 10-2 in./ft. and 2.96 x 10-2 in./ft., respectively. In other words, a belt produced with a flattened wire spiral is expected to elongate 172% more than a belt made with round wire.

CONCLUSION

The finite element analysis has helped to further the understanding of wire mesh conveyor belts. The measurement results show that belts made with flattened wire spirals are likely to be twisted and the angle of twist can be as great as 9.75 degrees. Results also showed the elongation to be 172% more and stress in the contact region to be 43% higher for belts made with flattened wire spirals rather than round wire spirals. This study did not take creep into consideration. Further studies are planned to include creep into the model.

REFERENCES

[1] A.S. Rabensteine, "Mechanical Properties of 310, 316, and 316L Stainless Steel Sheet Alloys at Elevated Temperatures", Dec. 1962, Report prepared for the Air Force: Contract No. AF33(657)-8706, Project 281, The Marquardt Corp., Van Nuys, CA [2] R.C. Hibbler, Mechanics of Materials, 3rd Edition, Prentice Hall, Upper Saddle River, NJ, 1994,

ACKNOWLEDGMENTS

The authors would like to thank Precision Calibration and Testing Corporation, York, PA, for preparing and measuring metallurgy type specimen mounts of furnace belts. Also, Donald J. Tillack, Nickel Development Institute, Toronto, Ontario, and Gaylord Smith, Specialty Metals, Huntington, WV, are acknowledged for their metallurgical assistance.

FROM THE MANUFACTURER

There are many components which affect the performance of a wire woven belt. Along with the geometry, material selection and manufacturing techniques are critical elements. W.M.P. continues to partner with Special Metals Corp. in the development of exotic test alloys. Other materials have been modified to provide greater belt life. Some of there materials are designed to perform up to 2300 degrees F. The belts are woven using special tooling and the wire is slowly drawn onto the blade with custom-made machines. This creates the lowest spiral ID in the industry. Lower spirals equal less stretch. Moreover, as belts stretch the grain structure changes and internal ruptures or voids develop. These voids allow for penetration of other elements and lead to premature belt failure. Wire-Mesh Products combines round wire geometry, state of the art materials, and low spiral profile manufacturing to maximize belt life. THERE IS A DIFFERENCE

Reprinted from the October 2000 Issue of INDUSTRIAL HEATING pages 1 2 3 4 5 Back