How increased vehicle weight can cause mobility problems and what to do about it.
The gross weight of a vehicle (GVW) directly affects mobility. Over time, weight increases can occur due to how the vehicle is operated, legislation changes, vehicle modifications and add-ons, resulting in unintended consequences for fleet owners and operators such as:
- Slower, less mobile vehicles.
- Reduced component life due to overloading.
- Increased maintenance costs.
- Increased fuel consumption.
Reducing GVW improves vehicle performance
Our weight reduction process includes:
- Defining a representative vehicle duty cycle and appropriate design criteria. Best results can be achieved by instrumenting a vehicle.
- Developing the overall concept design using our proven concept development processes.
- Calculating the expected results from first principles.
- Completing a “first cut” FEA of the components. Our engineers critically assess boundary conditions, mesh size and load inputs.
- Verifying FEA setup against the first principle results. An essential early step.
- Refining and finalizing the design based on the FEA results in accordance with the agreed design criteria. This is an iterative process.
- Building the prototype product from our Technical Data Package (TDP).
- Completing physical tests, including torque, fatigue and structural tests. Parts can be strain gauged to correlate actual results with FEA results.
- Revising and refining the TDP based on test results.
- Field testing. Again, parts can be strain gauged to correlate actual results with FEA results.
How it helps
On a recent project, we achieved an overall saving greater than 400kg across the full vehicle driveline. Importantly, we also maintained interfaces and exterior envelopes so new components could be retrofitted without changes to vehicle structure.
Need a quick solution to solve vehicle mobility problems?
There is no fixed timescale for this type of work. Our agile processes and flexible approach allow us to provide solutions to meet your requirements.
Keen to learn more? We’re always happy to chat, get in touch with one of the team here.
Why Independent Suspension Improves Vehicle Roll Performance
As a vehicle changes direction due to steering input, a lateral force causes the vehicle to lean in the opposite direction which may result in a vehicle rollover event (typically due to a combination of a high centre of gravity, speed, load shift and steering input).
You cannot change the Laws of Physics, so what can you do?
The roll-over threshold of a vehicle can be calculated from 1st principles and further analysed with dynamic modelling. While the Laws of Physics remain constant, vehicle OEM’s can take steps to reduce the risk of vehicle roll-over by increasing the roll-over threshold of a vehicle. Compared to a beam (live) axle, Independent Suspension (I.S.) provides significantly improved roll performance.
As shown below, roll stiffness for a beam axle is a function of the spring spacing squared, whereas roll stiffness for an I.S. is a function of the track width squared, and since t2 >> s2, the vehicle roll-over threshold is improved.
Advantageously, this increased roll stiffness can eliminate the need for a sway bar, thus further improving vehicle performance, especially off road. Depending on the type of I.S. on the vehicle, cornering performance is further improved with camber compensation provided by the suspension geometry.
Over 50 years of experience in understanding Vehicle Dynamics.
Timoney suspension systems allows vehicle drivers to operate safely and productively in on-road and off road environments. Roll performance can, of course, be further enhanced with the use of multi-rate springs, hydro-pneumatic struts and/or control systems. The theoretical performance of all these systems can be predicted using our proven state of the art dynamic modelling methodologies.
Interested in finding out more? Contact one of our team here.
Ride and Handling: Crucial for Vehicle Performance
Crucial for Vehicle Performance
Ride and Handling (R&H) is one of the most impactful day-to-day aspects of vehicle performance. So, what do we mean by Ride and Handling? In short, it is how a vehicle behaves during operation, how it responds to driver and terrain inputs and how this is reflected in driver confidence and comfort levels for vehicle occupants.
Ride quality is the degree to which occupants are isolated from vibrations and accelerations transmitted by bumps, potholes etc. Another factor to consider is drivability i.e., how the vehicle responds to driver and terrain input and how smooth and steady the vehicle remains when in motion.
Handling refers to the way a vehicle responds to driver inputs during events such as lane change manoeuvres, cornering, and its ability to keep the intended direction.
R&H influences key customer values such as safety, durability, productivity, occupant comfort, manoeuvrability, and on/off road performance. The challenge for vehicle OEM’s is to balance the conflicting R&H requirements i.e., the trade-off between a soft spring rate for ride quality and the need to control body roll during cornering.
R&H is also relevant to unmanned vehicles. By their nature, autonomous Unmanned Ground Vehicles (UGV’s) do not always follow the route that a human driver would and therefore may encounter hazards that could result in mission or vehicle system failures. The difference is you need to protect sensitive electronics instead of human beings!
All the above can be measured virtually or on a physical vehicle and must be evaluated together to ensure overall vehicle safety.
Timoney offers complete vehicle design
With a strong background in vehicle dynamics – and 50 years of global experience – we understand the design process from start to finish so we can make informed recommendations throughout the process.
We know that each vehicle OEM has its own criteria in evaluating ride and handling performance. We offer an independent and purely engineering-based view for our customers. In addition, our team of consultants have worked across all types of vehicles over the years, bringing a deep knowledge of the essential requirements for each vehicle type when it comes to ride and handling.
Sophisticated Modelling Techniques
We started using DADs for dynamic modelling in the mid-1980s to help us validate the design and make positive incremental changes to our designs. With advancements in dynamic modelling and vehicle technologies, we now use ADAMS to virtually model and collect data on vehicle motion and system information to determine and adjust the elements that contribute to overall vehicle performance, throughout the design stage
The range of both virtual modelling and vehicle testing methods we use considers differing driving styles and various weather / road conditions. We know that up to 80% of product development costs are determined by decisions made early in the design process. Our detailed testing ultimately saves customers considerable investment as we can finetune as we go, rather than apply remedial action at the end.
Customer-specific advice and direction
For our defence customers R&H translates into optimsed crew comfort, manoeuvrability and cross-country performance, ensuring your team arrive mission ready.
For customers in the construction sector, where personnel may have to spend up to 8 hours in the vehicle, R&H translates into operator confidence, which influences safety and productivity. We believe a safe machine means a productive operator.
With our customers in fire-fighting vehicles sector, R&H improves vehicle control and stability; boosting driver confidence and influencing safety.
For more information on Ride & Handling Services, or to talk to one of our team, contact us here
An immersive approach to technology transfer
For over 50 years, we’ve championed close working relationships with our clients, especially when it comes to transferring knowledge, technology and know-how. What we offer is the complete opposite of a plug-and-play approach.
Back in 1970’s, we developed a unique technology transfer model to mitigate any issue with transfer early in the design process. We wanted to ensure the success and smooth progression of local manufacturing.
With long and detailed production processes and timelines for heavy-duty vehicle components, time, consideration and engineering expertise is essential to ensure a smooth-running end product. This is our skillset – and we don’t expect our clients to grasp this overnight.
We like to do things differently at Timoney. We build collaborative client relationships, working as colleagues rather than assuming the traditional supplier-customer roles. We invite clients to send their manufacturing personnel, managers and engineers to come to our office and join our teams so that everyone – client and supplier – is learning on the job together. Client teams are brought into every aspect of the project from design to development, testing, sign-off and product delivery. We work together to select, test and refine the manufacturing components. This way, they can see first-hand any potential issues, and will be better equipped to make informed decisions when working with the technology at their local plant.
More can be assimilated through being immersed in the actual process than by clicking through a series of PowerPoint slides. Everyone leaves the process more technically educated; empowered to operate the technology independently.
And we know this process works. Our long-standing client relationships prove that this approach pays dividends –for us and for them – and this is across all sectors of our business; Defence, Construction and Fire.
It’s about building relationships, and providing an environment where knowledge is shared, rather than taught.
For more information on Technology Transfer, or to talk to one of our team, contact us here