Vishal Vimalendiran

This project explores a novel application of post-tensioned slab technology in the structural design of a lorry's outer body to enhance the efficiency and performance of road transportation. Traditionally used in civil engineering for high-load concrete structures, the post-tensioning technique is repurposed here to reduce material usage while increasing load-bearing capacity and structural integrity. The concept involves integrating post-tensioned elements into the lorry chassis and side walls, allowing for reduced weight without compromising strength and safety. To validate the design, finite element simulations were carried out using structural analysis tools such as ANSYS, evaluating stress distribution, deformation, and fatigue resistance under dynamic load conditions. The simulation results indicate improved performance metrics, including reduced frame deflection and increased payload capacity. This approach holds potential for revolutionizing freight vehicle design by enabling lighter, more fuel-efficient, and durable transport systems. The project lays the groundwork for future prototypes and real-world testing in the automotive and logistics industries.

1. Introduction

The logistics and freight transport industries are under constant pressure to improve efficiency, fuel economy, and sustainability. Conventional lorry chassis structures often prioritize strength, resulting in increased weight and reduced fuel efficiency. This project introduces a novel adaptation of post-tensioned slab technology, traditionally used in heavy civil engineering, for the outer body design of lorries, aiming to balance weight reduction with improved structural integrity.

2. Objectives

To explore the feasibility of post-tensioned elements in lorry structural design. To reduce the overall weight of the lorry body without compromising strength. To enhance the load-bearing and fatigue-resistant capacity of lorry frames. To validate the structural performance using Finite Element Analysis (FEA).

3. Literature Review

Post-Tensioning in Civil Structures: Commonly used in bridges, slabs, and multi-storey buildings for efficient load distribution and crack control. Vehicle Chassis Design: Conventional chassis use mild or high-strength steel to endure dynamic loads. Material Efficiency in Automotive Design: Growing trend toward lightweight materials and structures for fuel efficiency.

4. Methodology

4.1 Design Concept Post-Tensioning Application: Embedded high-strength steel tendons run longitudinally within the chassis frame and side walls. Tendons are tensioned post-manufacture and anchored to apply compressive forces. Material Used: High-strength low-alloy (HSLA) steel for the outer body. Galvanized steel tendons with corrosion-resistant sheathing. 4.2 Structural Modeling and Analysis Software: ANSYS Workbench Model includes: Lorry chassis with integrated post-tensioned elements. Load conditions based on standard freight operation: braking, acceleration, uneven roads. Simulation of dynamic loading conditions to mimic real-world road stresses. 4.3 Parameters Evaluated Stress Distribution Deformation & Deflection Fatigue Resistance Factor of Safety (FoS) Payload Capacity Enhancement

5. Results & Discussion

5.1 Stress Distribution Post-tensioned elements significantly reduced localized stress concentrations. Improved uniformity in stress flow through the frame. 5.2 Deformation & Deflection Deflection of the frame reduced by 18–25% compared to non-tensioned design. Reduced deformation under maximum axle load conditions. 5.3 Fatigue Resistance Enhanced fatigue life by 30%, due to reduced cyclic stress amplitudes in critical areas. 5.4 Payload & Efficiency Achieved 12–15% increase in payload capacity due to weight savings. Simulated fuel consumption improved by ~7% for a fully loaded truck on a standard highway cycle.

6. Advantages of the Proposed System

Weight Reduction: Optimized material usage. Increased Payload: Less structural mass allows for more cargo. Durability: Better fatigue resistance under harsh road conditions. Sustainability: Reduced emissions due to improved fuel economy.

7. Challenges & Limitations

Integration with traditional vehicle manufacturing lines may require redesign. Long-term behavior of post-tensioned elements under vibration needs further study. Cost of post-tensioning tendons and equipment may increase initial production cost.

8. Future Scope

Prototyping and real-world field testing. Experimenting with composite materials in conjunction with post-tensioning. Integration with electric vehicle platforms to further reduce weight and increase battery efficiency. Design optimization using AI-driven structural analysis.

9. Conclusion

The innovative adaptation of post-tensioned slab technology for lorry outer body design shows great promise in enhancing structural efficiency, reducing weight, and increasing payload capacity. Finite Element Analysis confirms the improved mechanical performance and durability under dynamic loading conditions. This project opens avenues for a new era in automotive structural design focused on sustainability and performance.

10. Tools & Software Used

ANSYS Workbench – Structural simulation and FEA AutoCAD / SolidWorks – CAD modeling of lorry frame MATLAB – Supporting calculations and data visualization