Why can a Megacasting not be repaired?

In my last posting, the most cited arguments against Megacastings were that you cannot repair that part, and the elongation is way lower. So, is that a problem for the driver and their passengers? No, the Tesla Model Y is one of the best cars in the NCAP crash test, with five stars.

So, let’s discuss how a Megacasting enables excellent crashworthiness even though a low(er) elongation is measured. And you will also learn why you cannot repair your Megacasting.

For that, we need to examine the mechanics in depth. Due to structural engineering principles and material behaviour, a single structure can have higher stiffness than one made of smaller pieces. Stiffness measures how resistant a structure is to deformation when subjected to an applied load.

A single, continuous structure allows for a more even distribution of loads. When loads are applied to a structure, they are distributed across the entire length or area, reducing localized stress concentrations. In contrast, a structure made of smaller pieces may have joints or connections that can create stress concentrations, making it more susceptible to deformation or failure. So, the load is transferred more efficiently from one point to another. The continuity of the material ensures that loads can flow through the structure without interruption.

So, let’s transfer the knowledge of mechanics and apply it to a crash situation. We all hope that we won’t be affected by a crash. Still, in that extreme case, we want the best survival chances.

In a collision, a car must absorb the energy the impact generates to reduce the forces transmitted to the occupants. A vehicle with a single, continuous structure can be engineered to have controlled deformation zones that help distribute and absorb energy more effectively. These zones can lead to a safer crash outcome, as the deformation can be designed to protect the occupants. 

A single, continuous structure is often better at dispersing impact forces across the entire vehicle body. This can help minimize localized points of high stress during a collision, reducing the risk of injury to passengers. In contrast, cars made of smaller pieces may have joints or interfaces that can be vulnerable to impact forces.

A continuous structure can help maintain structural integrity even after a collision. This is important because the structural integrity of the passenger compartment needs to be preserved to protect occupants. A single structure is less prone to separation or disintegration during a crash than a car with smaller, disconnected pieces.

Redundancy in the structure can be crucial for crash safety. A single structure with well-designed load paths can ensure that even if one part of the car is compromised in a crash, the overall structure can still provide protection. In contrast, cars made of smaller pieces may lack this level of redundancy.

And that is why you cannot repair your Megacasting!