Under Sleeper Pad with Cork-Elastomer Composite for Vibration Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing under sleeper pads with cork granulate-based elastic layers face limitations in vibration damping and stability due to the high stiffness of cork grains, necessitating an enhancement of their elastic properties for effective vibration damping and ballast protection.
Innovation Solution
Incorporating a cellular synthetic elastomer, such as polyurethane, into the elastic layer of under sleeper pads, either as a matrix embedding cork grains or as distributed grains connected by a binder, to optimize elastic properties and improve vibration damping while maintaining cost-effectiveness using waste cork products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cork grains of cork granulate are used in the elastic layer, then cost-effectiveness is improved by using waste products, but the elastic properties are insufficient due to high stiffness and plasticity of the cork grains
Solution Approach 1:
The patent creates a composite elastic layer combining cork grains with at least one other material (such as synthetic elastomers, rubber granulates, or thermoplastic elastomers). This composite structure allows the cork grains to provide cost-effectiveness while the additional materials compensate for the stiffness and plasticity issues, delivering the required elastic properties for vibration damping.
2Strength
If cork grains with high stiffness are used, then carrying function is improved, but vibration damping performance deteriorates due to insufficient elasticity
Solution Approach 1:
The patent applies local quality by having cork grains provide the carrying function (strength and stiffness) while the surrounding binding material provides the elastic properties needed for vibration damping. This spatial differentiation of functions within the elastic layer allows both requirements to be met simultaneously - cork grains bear the load while the matrix material absorbs vibrations.
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
The combination of cork grains and cellular synthetic elastomers enhances vibration damping and stability, providing effective ballast protection while allowing for cost-effective production, with improved elastic properties and reduced plastic deformation.
Implementation Method 1
an elastomer is a dimensionally stable but elastically deformable material which can be elastically deformed under tensile and/or pressure loading and then, after the loading has ended, however, at least predominantly returns to its original undeformed shape again
Implementation Method 2
For the purpose of vibration damping, under sleeper pads have at least one elastic layer
Data Source
AI summary
An under sleeper pad (1) to be fastened to an underside (3) of a sleeper (4), on the opposite side from the tracks (2). The under sleeper pad (1) has at least one elastic layer (5) having cork grains (6) of a cork granulate distributed throughout. In addition, the elastic layer (5) has at least one cellular synthetic elastomer (7).