Introduction

How can you be sure your product is ready for production? Developing something new can be very costly. Using a simulation tool in the developing process can provide you with vital information on how to proceed and prevents you from putting a lot of time and energy in redesigning your product.

Problem definition

Femto Engineering has been asked to evaluate the mechanical properties of the design of the “New York Kuipstoel” (New York Chair) for the Homefashion Group. For a product like this there are no ready sets of specific conditions and load cases available, so our engineers had to use alternate standards related to testing office chairs. The main question these tests were designed to answer was: is this design ready for production?

Approach

In order to formulate a set of load cases, our engineers used one of the NEN standards related to the testing of office chairs. The maximum permissible elongation and stresses were used as criteria to evaluate the seat. The simulations were performed on a Finite Element model consisting of 2nd order tetrahedral elements.

Conclusion

Our engineers were able to determine the proper thickness distribution of the plastic. A few iterations were needed. With the small iterations the chair will function properly in practice, without the necessity of changing the chair’s look. With this method, the mold for the injection molding process of the chair can be manufactured “first time right”. Simulations speed up the overall design process and can prevent potential (expensive) adjustments when production has commenced.