Designing for vehicle durability involves a comprehensive understanding of the loads that a vehicle’s structure is subjected to throughout its lifecycle. To achieve this, automotive engineers must analyze and predict the performance of the vehicle under various operating conditions and environments. Caliber Technologies has a significant expertise in the vehicle design and durability domain. The caliber process begins by identifying the high-level target of long-term durability, which is then broken down into more specific goals for each system and component of the vehicle. This hierarchical approach ensures that durability is considered at every stage of the design process, from the vehicle as a whole to its individual parts.
Cascading Durability Targets
The first step in this process is to establish the overall durability targets for the vehicle. These targets are typically defined by factors such as the vehicle’s expected service life, the number of miles it is expected to cover, and the types of road conditions it will encounter. Once these high-level goals are set, they are cascaded down to the vehicle’s systems—such as the suspension, drivetrain, and bodywork. Each system has its own set of requirements based on how it interacts with the overall vehicle performance and the forces it is subjected to.
At the next level, these system-specific targets are further refined into duty cycles, which describe the frequency and intensity of the various loads that each system will experience throughout the vehicle’s expected usage. For example, the suspension system’s duty cycle would account for the loads it experiences during normal driving, rough roads, or off-road conditions. Similarly, the drivetrain might have its own duty cycle that reflects the types of torque loads and operational stresses it will encounter.
Virtual Vehicle Modeling for Load Prediction
To accurately predict the dynamic loads on the vehicle’s structure, Caliber Technologies use advanced simulation techniques. One of the most powerful tools in this area is multibody dynamics (MBD) modeling. MBD is a computational approach that simulates the motion of interconnected rigid bodies under various forces, including road-induced forces, gravity, and forces from vehicle components interacting with one another. This allows engineers to model the entire vehicle, including its suspension, chassis, and drivetrain systems, as it travels across various road surfaces and conditions.
In an MBD simulation, a “virtual vehicle” is driven across a range of simulated road types—such as smooth asphalt, rough gravel, or uneven off-road trails. During these simulations, dynamic loads are calculated based on the vehicle’s motion, interactions with the terrain, and the forces acting on each component. These loads are essential to understanding how the vehicle will behave in real-world driving conditions and are used to inform the design process.
Accounting for Non-linearities and Other Complex Factors
Vehicle behavior is often nonlinear, meaning that small changes in conditions can result in disproportionately large changes in performance. This can be particularly important in durability design, as vehicle systems often experience large deformations or stresses in certain conditions that are difficult to predict. Multibody dynamics models are designed to account for these non-linearities, helping engineers accurately predict how the vehicle will perform under extreme or unusual conditions.
Additionally, vehicle systems exhibit stiffness characteristics that vary depending on factors like temperature, wear, and load. The frequency and amplitude of the loads also have a significant impact on how the structure responds. For example, loads that occur at higher frequencies may cause different material behavior compared to those at lower frequencies. Caliber Technologies incorporate these factors into their models to ensure that the simulations are as realistic and reliable as possible.
Durability Schedule and Early Design Integration
Once the loads are determined through simulation and the duty cycles for each system are defined, this information is combined to create a durability schedule. This schedule outlines the expected wear and tear for each component over time and provides guidance on the necessary design features, materials, and testing required to meet durability targets. By applying the durability schedule early in the design process, Caliber Technologies can make informed decisions about material selection, structural reinforcements, and other design considerations that will enhance the vehicle’s longevity.
The key benefit of this approach is that it allows potential durability issues to be identified and addressed long before the physical prototype is built. This proactive method can significantly reduce the risk of costly late-stage design changes or failures during real-world use. It also helps optimize vehicle performance and safety, ensuring that each system is robust enough to handle the expected stresses and loads without compromising reliability.
Conclusion
In conclusion, vehicle durability design is a multifaceted process that involves understanding the loads a vehicle experiences in various operating conditions. Through the use of sophisticated simulation tools like multibody dynamics models, Caliber Technologies can predict how the vehicle’s structure will respond to these loads and create durability schedules that guide design decisions from the very beginning. By considering critical factors such as non-linearities, structural stiffness, and frequency-dependent behaviors, Caliber Technologies can ensure that the vehicle is built to last, providing safety and reliability for years to come.