So NUS and HP are 2 teams that conducted the same test on an element body as shown above using a drop plate that falls at a velocity of 4.2 m/s on the element. The graph shown above shows the plot of a cushion curve which shows the deceleration vs psi of the drop plate. We are aiming to achieve HP's data for convergence but are not sure why the values are so different given we have matched their material properties of molded pulp product (something like cardboard). They are using the Radioss software with the James Cook model while I am using the Billinear Kinamatic model which also utilises the tangent modulus which i am not sure how to derive in this case. Do you have any suggestions have how to achieve convergence?