In English

Tränstryck på häst, Beräkning och simulering av tryck under nackstycke

Erika Engdahl ; fanny apelgren ; Nicolina Eklund ; Johanna Renman
Göteborg : Chalmers tekniska högskola, 2017. 69 s.
[Examensarbete för kandidatexamen]

The equestrian world is evolving and today we talk a lot about horse welfare and the importance of treating the horse with respect. A part of this is to ensure that the equipment for the horse is adapted and as comfortable as possible, something the company PS of Sweden has focused on with their ergonomic bridles. This project was aimed to compare PS of Sweden’s bridle to a traditional one based on the pressure distribution on the horse’s neck. In addition to this, a method for simulating how the pressure from the bridle spreads through the horse’s neck was to be developed. The project was divided into two parts, measurements and simulation. Measurements were done both with pressure sensitive Fujifilm and with pressure sensitive sensors from Tekscan. All measurements were performed on two different horses. The Fujifilm was used to produce a picture of the pressure distribution across the neck from both bridles. These measurements clearly showed higher pressure from the traditional bridle. In order to determine the value of the pressure underneath the headpieces, Tekscan sensors were used and measurements were performed during all the horse’s gaits. This showed that the traditional bridle gave more than double the pressure for both test horses. To simulate the pressure distribution on the horse’s neck, software from the software company BETA CAE Systems was used. The project used three of BETA CAE Systems software; RETOMO, ANSA and mETA to develop a model of a horse’s neck and to simulate the pressure distribution of the bridle’s headpiece. Additional softwares outside the BETA CAE Systems range were also used. With the help of RETOMO, the project converted medical, computer-tomographic images of a horse head to a simple three-dimensional model. The model was simplified by being cut and restricted to contain only two types of material, flesh and bone. The ANSA pre- processing program was used to improve the model and prepare simulation calculations in the external program Abaqus. After performing calculations, the results were visualized and analyzed in the mETA post-processing program. All steps were well documented to create a method for future simulations of similar cases. The result was a simple model of a horse’s neck which, in simulations, was loaded with a pressure corresponding roughly to the pressure of a headpiece. Despite the simplification of both the model and the loads, the calculations converged in a promising manner, suggesting that there is potential for further development of the method in order to be able to test new equipment for horses in a satisfactory manner in the future. From the measurements of pressure distribution from the two different headpieces, we see that the wider headpiece of PS of Sweden’s bridle gives a lower pressure. In the 3D-model, we can see that there are two areas on the neck where the skeleton is very superficial, we think that a good headpiece should avoid putting pressure on these areas while being big enough to reduce the pressure across the neck.

Nyckelord: equestrian, bridle, headpiece, PS of Sweden, RETOMO, ANSA, META, Abaqus