Rail Vehicle Crash System with Composite Energy Conduction
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Solution Overview
Problem
Existing rail vehicle crash systems face challenges in efficiently dissipating impact energy and transmitting forces during normal operation while avoiding damage to fibre-reinforced plastic materials and ensuring safety by preventing fragment formation and lever actions on the roof construction.
Innovation Solution
A crash system featuring a lower crash conduction element with a crash box and central buffer coupling that conducts remaining impact energy into the underframe support of the following coach section, utilizing fibre composite materials and a telescopic central buffer coupling for energy absorption, and a two-shell construction with predetermined breaking points to minimize fragment risk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fibre-reinforced plastic materials are used in the head module construction, then material and energy efficiency is improved, but the materials are susceptible to damage from compressive loads during crash events
Solution Approach 1:
The head module is divided into a two-shell construction with an outer shell and an inner shell, where each shell has specific functions. The outer shell provides structural integrity and crash energy management, while the inner shell contains the passenger compartment. This segmentation allows the outer shell to be designed specifically for crash energy absorption without compromising the integrity of the inner shell.
Solution Approach 2:
A crash conduction element is introduced as an intermediary component between the outer shell and the inner shell. This element manages the transmission of crash forces, conducting impact energy from the outer shell into the inner shell in a controlled manner, preventing direct compressive loading of the fibre-reinforced plastic materials in the inner shell structure.
2Force
If a continuous substructure runs through the entire coach, then force transmission during normal operation is improved, but complex systems are required to manage both normal operation forces and crash energy
Solution Approach 1:
The outer shell is designed to serve multiple functions: it provides the external aerodynamic shape, contains the crash energy management system, and transmits forces during both normal operation and crash events. The crash conduction element similarly serves dual purposes by maintaining structural integrity during normal operation while actively managing crash energy transmission. This multi-functionality reduces the need for separate dedicated systems.
Solution Approach 2:
The system transitions from a static structural design to a dynamic crash response system. During normal operation, the outer shell and crash conduction element maintain their structural integrity for force transmission. During a crash, the system dynamically responds by allowing controlled deformation and energy absorption in the outer shell, then conducting the remaining energy into the inner shell through the crash conduction element.
3Loss of energy
If energy absorption elements are arranged in the vehicle front-end, then impact energy is absorbed, but lever actions can be generated on the roof construction
Solution Approach 1:
The crash energy management function is extracted from the traditional front-end energy absorption elements and relocated to the outer shell and crash conduction element system. By positioning the crash conduction element underneath the inner shell and arranging it to extend into the following coach section, the system absorbs and conducts impact energy without creating lever actions on the roof construction.
Solution Approach 2:
The crash conduction element is arranged in a different spatial dimension - underneath the inner shell rather than in the front-end above the roof. This dimensional relocation allows impact energy to be absorbed and conducted through the lower structure, preventing the generation of lever actions that would affect the roof construction.
4Ease of manufacture
If prefabricated modules are attached to the substructure, then manufacturing efficiency is improved, but the fibre-reinforced plastic materials between reinforcing profiles and underframe are subjected to compressive loads
Solution Approach 1:
The outer shell is designed with integrated crash energy absorption capabilities that absorb impact energy before it can be transmitted to the fibre-reinforced plastic materials in the inner shell. This beforehand cushioning protects the fibre materials from compressive loads during crash events while maintaining the prefabricated module construction for ease of manufacture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design simplifies the installation and enhances the safety and efficiency of force transmission during both normal operation and crashes by avoiding complex systems and reducing the risk of fibre material damage, effectively diverting impact energy into the coach section.
Implementation Method 1
The purpose of this device is to absorb a portion of the impact energy and to convert it into material deformation in the event of a crash
Implementation Method 2
The arrangement of the fibres without a preferred direction guarantees that the impact energy is converted when the fibres are broken down
Data Source
AI summary
The application relates to a crash system for the head module of a rail vehicle, said head module being detachably fixed to the front face of a subsequent railcar unit without additional underframe. The crash system has a crash conduction element that carries a crash box at its front end and the back end of which is fixed to the underframe support of the subsequent railcar unit. In the event of a crash, crash forces are thus absorbed by the underframe of the subsequent railcar unit.