WO2017158227A1

WO2017158227A1 - System and method for the dynamic characterisation of railway superstructure elements and computer program

Info

Publication number: WO2017158227A1
Application number: PCT/ES2017/070159
Authority: WO
Inventors: Jordi ROMEU GARBÍ; Arnau CLOT RAZQUIN; Robert ARCOS VILLAMARÍN; Jordi SANS GARCIA
Original assignee: Universitat Politècnica De Catalunya
Priority date: 2016-03-18
Filing date: 2017-03-17
Publication date: 2017-09-21

Abstract

The invention relates to a system for the dynamic characterisation of railway superstructure elements, comprising an exciter device that can be connected to a railway superstructure. According to the invention, the exciter device comprises: vibration and load generating means; means for processing data from load sensor means; and vibration acceleration sensor means, which can be positioned in a component of the superstructure. The method of the invention comprises: generating a tonal excitation and a load (F3) on an element of the superstructure; measuring the load (F3) or dynamic sinusoidal force applied to an element of the superstructure and the acceleration of the vibrations induced in an element of the superstructure; and inverting an analytical superstructure model based on the measured acceleration.

Description

DESCRIPTION

System and method for dynamic characterization of elements of railway superstructures and software

OBJECT OF THE INVENTION

The purpose of this application is to register a system and method for dynamic characterization of elements of railway superstructures, as well as a computer program to carry out said method that incorporates notable innovations.

More specifically, the invention proposes the development of a mobile plant system and a corresponding method that falls within the field of the study of the dynamic characterization of superstructures.

BACKGROUND OF THE INVENTION

A railway superstructure includes a set of elements that go from the rail to the platform on which the track sits. Each of these elements determines the performance of the railway superstructure in terms of safety (stability and reliability of the superstructure), environmental impact (generation and propagation of noise and vibrations) and maintenance costs (growth of road roughness, wear wave, degradation of the ballast, damage to the sleepers and fasteners ...). Consequently, knowledge of the dynamic stiffness and damping properties of each element is essential to predict the performance of a railway superstructure at the project stage as well as to optimize the maintenance of functioning superstructures, so that they remain within the safety margin and environmental impact for which they were designed. In general, stiffness and damping should be determined from dynamic tests in the appropriate frequency range. Static deformation tests do not allow the determination of damping or dynamic stiffness.

It is possible to characterize the majority of components through dynamic laboratory tests, using specific procedures and equipment for individual elements ^{[1 "41} or more complete test plants that include superstructure ^{1 ■} However, the on-site testing of railway superstructures is an inevitable practice in the case of existing infrastructure for which one wishes to take into account the particularities of the already implemented superstructure and the effects of interaction between all the elements. There are different in situ tests of railway superstructure that can be classified as partial or global tests.

Partial tests are those that allow determining the dynamic properties of some components of the railway superstructure. Specifically, it is possible to distinguish between the tests to characterize elements of the superstructure (rail, support, ballast, crossbar) and the tests to characterize the substructure (sub-ballast, platform, terrain)

The most common procedure to characterize elements of the superstructure consists of the impact test by means of an instrumented hammer. The rail is excited by an impact with a hammer that contains a load cell capable of recording the force performed. The response of the system to said excitation is measured by accelerometers at different points of the superstructure. The transfer function between the impact force and the displacement is compared with a mathematical model of the superstructure dynamics, such as a system of two degrees of freedom ^m , or a numerical model of a limited section of track ^{[3]. , 81} . By optimizing the parameters of the mathematical model to fit the experimentally obtained transfer functions, it is possible to obtain an approximation to the values of the desired dynamic properties. The main problems of this procedure are its inability to excite the complete superstructure (so it is only possible to analyze the behavior of the rail, clamping and crossbar ^[9] ), the inability to excite the system below 50 Hz, thus as the impossibility of determining the behavior of the elements under a static load equivalent to the weight per axis, a factor that alters the properties to be determined ^{[2, 3]} . The substructure properties are tested using standardized land characterization procedures in general, such as the SASW test or the "crosshole / downhole" seismic, which require specific and different equipment and procedures from the soil test. superstructure. The overall test of the response of a railway superstructure is currently achieved by a car equipped with equipment for reading the deformation of the track under the weight of the car itself. With this type of vehicles ("Track Loading Vehicle", TLV) the static stiffness of the superstructure as a whole is determined, but in no case is the individual characteristics of each constituent element of the superstructure nor the frequency response found since the excitation is the simple static load of the car. A complete TLV relationship can be found in the reference ^[0] .

A variant of these TLVs is the self-styled "Portancemetre" that allows determining the rigidity of the railway superstructure for a limited range of frequencies. The system uses a system of unbalanced counterbalanced masses installed in a chassis, which generate a vertical oscillating force. This force is transmitted to the track through the wheel-rail contact that equips the system. The calculation of the transmitted force is estimated indirectly from the measure of acceleration in one of the system's masses.

A step forward between TLVs is the rolling stiffness measurement vehicle (RSMV), which is capable of dynamically exciting the railway superstructure up to 50 Hz by using two oscillating masses moved by hydraulic pistons and located in the vertical of one of the axes that support the wagon ^[0] . The dynamic stiffness of the superstructure as a whole is calculated from the measurement of transmitted force and acceleration of the contact axis itself. If the stiffness found as a function of frequency is compared with the response of a simplified model of a railway superstructure composed of a beam on elastic ground, the properties of these equivalent elements can be estimated ^{[12, 3]} , but the properties cannot be determined of each of the elements that really constitute the railway superstructure.

There are patented portable devices that aim to excite the track. Application WO 20117015687 (A1) ^[] uses the vibrations produced by imperfections in the contact surfaces of a wheel rolling on rigid elements. The vibrations produced are transmitted to the ground through the rigid frame of the system. The objective of the equipment is, however, the simple excitation of the track to determine the propagation of vibrations in the railway environment and not the characterization of the track elements. Nor is the force exerted on the track controlled. DESCRIPTION OF THE INVENTION The present invention has been developed in order to provide a system, a method and a computer program that solve the aforementioned drawbacks, also providing other additional advantages that will be apparent from the description that accompanies continuation. In the present invention, a superstructure component is understood as any element that is part of it, such as a rail, a rail fastener, a ballast or block, a sleeper, etc. In addition, the vertical, horizontal, frontal, posterior, lateral, axial senses must be considered in a condition of use. An object of the present invention is a mobile plant system for dynamic characterization of railway superstructure elements comprising:

an exciter device linked to a railway superstructure, in which the exciter device in turn comprises vibration and load generating means arranged in a bed that is linkable at least to one track through at least one coupling means to the superstructure as a support; Y

data processing means in communication with a load sensing means and a vibration acceleration sensing means, in which the load sensing means are arranged at least in a support and the vibration acceleration sensing means are susceptible to position at least one component of the superstructure.

Thanks to the aforementioned characteristics, a simple and portable mobile plant system is achieved that allows to dynamically accurately characterize each and every one of the components of a railway superstructure. The present system is directly applicable on the railway superstructure, does not require a wagon, and allows the whole process of characterization of the superstructure to be integrated without the need for other devices. The data of the load and acceleration of the vibration applied on the chosen components of the superstructure are collected and processed. According to a feature of the invention, the vibration and load generating means may comprise at least one pair of counter-rotating disks of mass arranged unbalanced with respect to their respective axes of rotation, in which the disks are driven by less a drive unit, in which a first disk is linked to the drive unit through a power or primary transmission, and the second disk is linked to the drive unit through a synchronized or secondary transmission. With this configuration, a simple and efficient alternative to apply exclusively vertical loads and tonal excitation directly to the superstructure is achieved.

The pair of discs may comprise holes, recesses or protuberances positioned eccentrically, and capable of carrying inserts of determined masses. Thanks to this feature it is possible to modify the load applied to the superstructure depending on the needs, simply and quickly.

On the other hand, the vibration and load generating means are configured to vary their frequency. In this way, a system that varies tonal excitation within a given interval can be achieved, in addition to the variation of the load. In one embodiment the load sensing means may comprise a load cell.

As for the vibration acceleration sensing means, they may comprise a plurality of positionable accelerometers in a superstructure with a ballast track, such that at least one accelerometer is capable of being positioned in a rail fastener, another between a pair of sleepers, another in one naughty and another in a land adjacent to a ballast.

Alternatively, the vibration acceleration sensor means may comprise a plurality of positionable accelerometers in a plate track or floating slab superstructure in which a track is subject to a plurality of blocks arranged on at least one plate, such that at least An accelerometer is capable of positioning itself in a rail fastener, another between blocks, another in a block, another in the plate and another in a land adjacent to the plate. The coupling means by way of support can be advantageously mobile with respect to the bed. In this way the present mobile plant system can be positioned on tracks with different widths from each other. Another object of the present invention is a method for dynamic characterization of railway superstructure elements comprising the steps of:

a) generate at least one tonal excitation and a load on an element of the superstructure,

b) measure the sinusoidal dynamic load or force applied on at least one element of the superstructure and the acceleration of the vibrations induced in at least one element of the superstructure,

convert an analytical or numerical superstructure model based on the acceleration measured in stage b). Thanks to these characteristics, a method is achieved to achieve a simple and precise characterization of the components of the railway superstructure. The present method allows to fully control the force that runs on the track, as there are no other ways of transmitting force between the machine and the track. The element of the superstructure to which the face is applied can be at least one way.

In a preferred embodiment of the method of the invention, the analytical or numerical model of the superstructure is determined according to the following formula: Ü (x _u ) = Φ (ρ, F (x _f )), Formula 1

Where:

Ü (x _u ) is the vibration acceleration in a given frequency domain for at least one evaluation position x _u at a point in the superstructure,

Φ is the operator that represents the analytical or numerical model,

p is at least one input variable of the analytical or numerical model and

F (x _f ) is at least one dynamic sinusoidal force in the determined frequency domain and applied over at least a certain excitation position x _f in the superstructure. Preferably, the variable p may be at least the value of the dynamic stiffness or the damping of each component of the superstructure. Preferably, in step c) at least one parameter p of Formula 1 is calculated, minimizing a real part:

Re (Ü _theo (x _u ) - Ü _exp (x _u )),

and an imaginary part:

lm (Ütheo (x _u ) - Ü _exp (x _u )), considering that F _theo (x _f ) = F _exp (x _f ),

in which

Ü _theo (x _u ) is a vibration acceleration previously estimated from an analytical or numerical model Φ,

F _theo (x _f ) is a previously determined sinusoidal dynamic force,

Ü _exp (x _u ) is a vibration acceleration measured experimentally in a given frequency domain for at least one evaluation position x _u at a point in the superstructure,

^F exp ( ^x _f ) ^{is a} dynamic sinusoidal force measured experimentally in the determined frequency domain and applied over at least a certain excitation position x _f in the superstructure.

This way, the input variables of the analytical or numerical model, typical of a superstructure, are known. This model Φ can be of two-dimensional or three-dimensional type.

The tonal excitation of stage a) can advantageously occur in a frequency range between 1 and 80 Hz. And even more advantageously, the tonal excitation of stage a) can occur in a frequency range between 10 and 80 Hz.

A further object of the invention is a computer program comprising program instructions for making a computer system perform the method for dynamic characterization of railway superstructures as defined above.

Said computer program may be included in storage media, such as recording media, a computer memory, or a read-only memory, or it may be carried by a carrier signal. Other features and advantages of the mobile plant system for dynamic characterization of railway superstructure elements, as well as the method followed and the computer program objects of the present invention will be apparent from the description of a preferred, but not exclusive, embodiment. illustrates by way of non-limiting example in the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1.- It is a schematic and front perspective view of an exciter device of the present invention;

Figure 2.- It is a schematic and rear perspective view of the exciter device of Figure 1;

Figure 3.- It is a schematic and front view of the exciter device of Figure 1;

Figure 4.- It is a schematic and rear view of the exciter device of Figure 1;

Figure 5.- It is a schematic and side view of the exciter device of Figure 1;

Figure 6.- It is a schematic and plan view of the exciter device of Figure 1;

Figure 7.- It is a schematic and front view of a mobile plant system of the present invention, arranged in a railway superstructure;

Figure 8.- It is a schematic view from below of the exciter device with the supports in a first position;

Figure 9.- It is a schematic and side view of the exciter device of Figure 8;

Figure 10.- It is a schematic view from below of the exciter device with the supports in a second position;

Figure 1 1.- It is a schematic and side view of the exciter device of Figure 10;

Figure 12.- It is a schematic elevation view of a support;

Figure 13.- It is a schematic sectional view of the support of Figure 12 according to the cutting line A-A ';

Figure 14.- It is a schematic and side view of the support of Figure 12; Y

Figure 15.- It is a schematic sectional side view of the support of Figure 12 along the line B-B '.

DESCRIPTION OF A PREFERRED EMBODIMENT As shown in the accompanying figures, a preferred but not exclusive embodiment of the present invention is illustrated.

In Figure 7, in which some elements have been removed for reasons of clarity, it can be seen that the present mobile plant system 100 for dynamic characterization of railway superstructures 200 comprises an exciter device 1 linked to a railway superstructure 200. The connection in the mobile plant system 100 and the superstructure 200 is preferably carried out directly, without the intervention of other devices or assemblies, such as a modified wagon or wagon.

The exciter device 1 in turn comprises vibration and load generating means arranged on a bench 30 that is linkable to at least one track 201 through at least some coupling means to the structure as a support 40. The bench 30 may comprise a plurality of profiles on which a laminar element rests, defining a platform, as seen in the images. It is not ruled out that the present exciter device 1 can be linked or resting on other components of the superstructure 200

In the present preferred embodiment the vibration and load generating means comprise a pair of counter-rotating discs 21, 22 with a mass arranged in an unbalanced manner with respect to their respective axes of rotation. This unbalanced mass causes that when rotating a load is generated on the superstructure 200 with a certain vibration. It is clear that the number of discs can be changed depending on the needs. To be able to rotate in the directions R1, R2, the disks 21, 22 are driven by a driving unit 23, in this case an electric motor with a variable operating speed to be able to modify the frequency of the vibration generated on the superstructure 200.

A first disk 21 is linked to the drive unit 23 through a power transmission 27 or primary, and the transmission is preferably carried out by trapezoidal belts, with the double purpose of preventing transfer of operating vibrations between motor and discs 21, 22 and make the exchange of pulleys easier. Both discs 21, 22 are installed on bearing supports to facilitate rotation. It can be seen in Figure 6 that the drive unit 23 drives the first disk 21 through the power transmission 27, so that it rotates around its axis E1. From the first disc 21 the movement is transmitted to the second disc 22 by means of a synchronized transmission 24 or secondary. In this case, the synchronization transmission 24 can be a plurality of gears (not shown) that can vary the synchrony between discs 21, 22, however it is preferred that said synchrony is 1/1.

To easily vary the mass distributed unbalanced by the structure of the discs 21, 22, these discs 21, 22 comprise two threaded holes 26 positioned eccentrically and capable of carrying inserts 25 of determined masses. Alternatively, other variants such as recesses or protrusions can be used to position the inserts 25. The shape of the inserts 25 in the present invention is elongated with a threaded tip (not illustrated) capable of being threaded into the corresponding hole 26. As already mentioned, the inserts 25 are the causes of the imbalance of the discs 21, 22 and, consequently, of the generation of the excitation force with a pair of components: horizontal F1 and vertical F2. To ensure that the horizontal component F1 of this force is not significant, the holes 26 are located symmetrically with respect to an axis of symmetry between the two disks 21, 22 and the masses of the inserted inserts 25 are exactly the same for the two disks 21 , 22. The opposite directions of the two rotations R1 and R2, estimating discs 21, 22 with twin inserts 25, get the horizontal components F1 to cancel each other out.

Other methods may be used to generate the vibrations and the vertical load on the superstructure, such as for example a pair of oscillating masses moved by hydraulic pistons (embodiment not shown), or driven by electric motors synchronized with each other.

The present mobile plant system 100 further comprises data processing means (50) in communication with load sensing means 6 and vibration acceleration sensing means 7. Load sensing means 6 are preferably arranged in each support 40 and the vibration acceleration sensor means 6 are capable of positioning at least one component of the superstructure 200. In the embodiment shown, four supports 40 are used to link the bench 30 to quadrilateral mode on tracks 201 of superstructure 200, however the number of supports 40 may vary according to the requirements of each situation.

. In Figures 8-1 1, the exciter device 1 can be seen with a bench 30 provided with a series of holes 31 or the like where the supports 40 can be linked by means of unrepresented screws that cross the openings 43 associated with the holes 31. Between the figures 8 and 10 the different position of the supports 40 can be clearly seen. In figures 12-15 the configuration of a support 40 is illustrated in more detail. The support 40 comprises a first base 41 linked to a second base 42 rotatably as a hinge. Between the first base 41 and the second base 42, the load sensing means 6 are arranged. To prevent damage to said means, a pair of positionable stems 44 are also arranged so that the relative distance between the first base 41 is adjusted. and the second base 42. When measurements are not desired, the rods 44 separate both bases and when it is desired to measure the applied load, both bases are approximated again. The supports 40 also have at least one screw 45 for height adjustment of the support with respect to the component of the superstructure to which it is linked, for example track 201. In addition, each support 40 comprises a plate 46 for lateral contact with track 201.

In order to be able to know at all times the vertical load F3 (compression stresses) that is applied on the superstructure 200, the load sensing means 6 comprise a load cell, preferably located in each of the supports 40. These load cells are configured to only convey information about axial stresses.

In a possible example, the vibration acceleration sensing means 7 may comprise a plurality of positionable accelerometers in a superstructure 200 with a ballast track, that is to say that railway track seated on ballast 204. Thus, an accelerometer can be positioned in a rail fastener 202, another accelerometer between a pair of sleepers 203, another accelerometer in a sleeper 203 and another accelerometer in a land adjacent to a ballast 204.

In another example, the vibration acceleration sensor means 6 may comprise a plurality of positionable accelerometers in a plate track superstructure 200 or floating slab in which the track 201 is subject to a plurality of blocks arranged on at least one plate, such that at least one accelerometer is capable of being positioned in a rail fastener 202, another between blocks, another in a block, another on the plate and another on land adjacent to the plate.

The term "adjoining" means close, so that the accelerometer is able to adequately capture the acceleration of the generated vibration.

In view of the examples analyzed, it can be confirmed that the number and location of the vibration acceleration sensor means 7 will be variable depending on the type of superstructure 200 and the level of detail required in the study. To perform an accurate characterization, the accelerometer network must be sufficiently extensive to capture all the dynamic singularities of superstructure 200. This implies that a minimum of one accelerometer should be placed per component of superstructure 200.

The exciter device 1 can be ballasted for example up to a maximum total added weight of 6 tons. Thus, the non-linear behaviors of elastomeric materials existing in the most modern railway superstructures 200 can also be characterized. The dynamic stiffness and damping of the aforementioned elastomeric materials (blankets under plate, certain fasteners) depend on the load to which they are subjected, mainly the weight that falls on the wheel which in turn depends on the type of train. In the present invention, the exciter device 1 can be loaded so that the axle weight of various types of rail can be emulated and the influence of the weight on the stiffness and damping value can be detected.

In order to dynamically characterize railway superstructures 200, a method is followed with a series of main stages. Preferably, a mobile plant system 100 will be employed as described above.

The method comprises the steps of: a) generating at least one tonal excitation and a load F3 on a path 201, as a preferred example of a component of the superstructure 200 (it could be another). This stage can occur when the discs 21, 22 are provided with counter-rotation, respectively provided with a insert 25 of predetermined mass. By varying the mass of the inserts 25, the load F3 or compression force that is applied on the superstructure 200 to be characterized may be varied. The drive and regulation of the drive unit 23 are preferably managed by the processing means 50, although it can be done manually by the operator. At this stage, tonal excitation on track 201 can occur in a frequency range between 1 and 80 Hz, and even more preferably in a frequency range between 10 and 80 Hz following the provisions of ISO 2631- 2. It is evident that such intervals may vary; b) measure the load F3 or dynamic sinusoidal force applied on track 201 and the acceleration of the vibrations induced in at least one element of the superstructure 200. The information is received in the processing means 50, from the plurality of sensors ; c) invert an analytical or numerical model of superstructure 200 based on the acceleration measured in step b). The analytical or numerical model of the superstructure 200 that is preferably used is determined according to the following formula:

Ü (x _u ) = (p, F (x _f )), Formula 1 in which Ü (x _u ) is the vibration acceleration in a given frequency domain for at least one evaluation position x _u at a point in the superstructure 200,

Φ is the operator that represents the analytical or numerical model,

p is at least one input variable of the analytical or numerical model, such as dynamic stiffness and / or damping of at least one component of the superstructure, and

F (x _f ) is at least one dynamic sinusoidal force or load F3 in the determined frequency domain and applied over at least a certain excitation position x _f in the superstructure 200.

Continuing with stage c). In order to invert the analytical or numerical model and thus know the parameter (s) that characterize a specific superstructure 200, the parameter p of Formula 1 is calculated, minimizing a real part of the difference: Re (Ü _theo (x _u ) - Ü _exp (x _u )), and an imaginary part of said difference expressed: lm (Ü _theo (x _u ) - Ü _exp (x _u )). All this can be done considering that F _theo (x _f ) = F _exp (x _f ) In the aforementioned expressions:

F _theo (x _f ) is a previously determined sinusoidal dynamic force,

Ü _exp (x _u ) is a vibration acceleration measured experimentally in a given frequency domain for at least one evaluation position x _u at a point of superstructure 200,

^F exp ( ^x _f ) ^{is a} sinusoidal dynamic force measured experimentally in the determined frequency domain and applied over at least a certain excitation position x _f in superstructure 200. It is understood that this dynamic sinusoidal force will be received from the four cells of load arranged respectively in each of the supports 40. The suffixes "theo" refer to theoretical values that are estimated to apply the analytical or numerical model like that of Formula 1. Next and selecting the same evaluation and excitation positions that in the theoretical model, the experimental values referred to with the suffix "exp" are obtained. And as said before, it can be considered that F _theo (x _f ) = F _exp (x _f ), otherwise, that is, if the load F3 differs from the estimated theoretical value, the mass of the insert 25 must be adjusted so that apply the appropriate F3 load for the calculation.

Once the appropriate values of "p" are obtained, for example through an algorithm, it is possible to apply an analytical or numerical model such as that of Formula 1 that can accurately characterize each and every one of the components of a superstructure 200 analytically

The models Φ must be correctly chosen according to the type of superstructure 200 to be characterized and the level of accuracy in the required characterization. The more detailed analytical or numerical models, which may allow more precise characterizations, are more computationally expensive, so a compromise appropriate to the needs of the study must be reached. The models Φ implemented for the realization of the present mobile plant system 100 can be classified into two large branches according to their complexity: - Two-dimensional superstructure models: These models do not take into account the dynamic variability of the superstructure in the transverse direction (with respect to the direction of advance) to track 201 with the exception of the terrain, which is three-dimensional. Its calculation speed is very high. These models are based on the adaptation of the model presented in ^[5] to all major types of railway superstructures.

- Three-dimensional superstructure models: They arise from the adaptation of the model presented in ^[6] to all the major types of railway superstructures, although with a higher computational cost than the previous models. Three-dimensional FEM (finite element method) models can also be used for the same purpose, which entail a higher computational cost but allow a more accurate representation of the geometry of the problem and, consequently, better results in dynamic characterization ^[7] . It should be mentioned that theoretically F2 can be of the same magnitude as F3. However, in practice, the dynamic response of elements such as bench 30 can alter this equality. So you can consider that F2 = F3 are approximately equal but it is necessary to have the value of F3. F3 is distributed among the different supports 40 presented by the invention, in this case there are four, so that F3 is the sum of the vertical load applied through each of the four supports 40. It is important to clarify that if Fi is the vertical load of each of the supports 40, this can vary between the same supports 40. If you work with a two-dimensional model, the most appropriate is to use a single F3 and if you work with a three-dimensional model, you could work with some more accurate and detailed F3 data for each support 40. This in turn allows a more precise identification of the magnitudes sought.

A computer program is also provided that comprises program instructions to make a computer system, such as processing means 50, perform the method for dynamic characterization of railway superstructures 200 as defined above.

Said computer program may be stored in physical storage media, such as recording media, a computer memory, or a read-only memory, that is, any entity or device capable of carrying said computer program. The computer program can also be carried by a carrier signal, such as electrical or optical, which can be transmitted via electrical or optical cable or by radio or other means.

The details, shapes, dimensions and other accessory elements, as well as the materials used in the manufacture of the objects of the invention may be conveniently substituted by others that do not depart from the scope defined by the claims included below.

REFERENCES

[1] Jaroslav Smutny, Measurement and analysis of dynamic and acoustic parameters of rail fastening NDT & E, 37, 1 19-129. 2004,

[2] J. Maes, H. Sol, P. Guillaume, Measurements of the dynamic railpad properties.

Journal of Sound and Vibration 293 (2006) 557-565.

[3] Stefano Bruni & Andrea Collina. Modeling the Viscoelastic Behavior of Elastomeric

Components: An Application to the Simulation of Train-Track Interaction. Vehicle

System Dynamics: 34 (2000) 283-301.

[4] S. Kaewunruen and A.M. Remennikov An alternative rail pad tester for measuring dynamic properties of rail pads under large preloads. Experimental Mechanics,

48 (1): 55-64, 2008.

[5] C. Guigou-Carter, M. Villot, B. Guillerme, and C. Petit. Analytical and experimental study of sleeper SAT S 312 in slab track Sateba system. Journal of Sound and Vibration, 293 (3-5): 878-887, 2006

[6] Van Honacker P., Goossens A. Banc d'essai pour voie ferrée. BE 1014836 (A6).

Invention patent, 2002.

[7] S. Kaewunruen, A. Remennikov. Field triáis for dynamic characteristics of railway track and its components using impact excitation technique. NDT & E 40, 510-519. 2007

[8] De Man, AP; Esveld, C. Recording, estimating and managing the dynamic behavior of railway structures. Proceedings of the International Seminar on Modal Analysis. KU Leuven; 1998, 2001. p. 749-754. [9] M. Oregui, M. Molodova, A. Núñez, R. Dollevoet, Z. Li, Experimental Investigation Into the Condition of Insulated Rail Joints by Impact Excitation. Experimental Mechanics 2015.

[10] E.G. Berggren Railway Track Stiffness. Dynamic Measurements and Evaluation for Efficient Maintenance. PhD thesis, Royal Institute of Technology (KTH), Stockholm,

2009

[1 1] Mohsen Hosseingholian, Daniel Levacher and Matoren Khay, Mesure en continu de la raideur dynamique d'une voie ferrée. Rev. can. geotech vol. 48, 439-450, 201 1.

[12] C. With, A. Bodare, Evaluation of track stiffenss with a vibrator for prediction fo train induced displacements or railway embarnkments. Soil Dynamics and Earthquake

Engineering, 29, 1187-1197. 2009

[13] Eric G. Berggren, AmirM. Kaynia, Bjórn Dehlbom Identification of sustructure properties of railway tracks by dynamic stiffness measurements and simulations. Journal of Sound and Vibration, 329, 3999 ^ 1016. 2010

[14] Fenollosa Artes F., Goma Ayats J., Martínez Miralles J. and Cardona Foix, S .. Method for the diagnosis of the level of vibration transmission from a transit surface of railway vehicles and test bench for its implementation. WO 201 17015687 (A1). Invention patent, 2009.

[15] R. Arcos. A model for railway induced ground vibrations in the frame of preliminary assessment studies, Ph.D. Thesis, Polytechnic University of Catalonia, 201 1.

[16] A. Karlstróm, A. Bostróm. An analytical model for train-induced ground vibrations from railways, Journal of Sound and Vibration, 292 (1-2) (2006) 221-241.

[17] M Oregui, Z Li and R Dollevoet, An investigation into the vertical dynamics of tracks with monoblock sleepers with a 3D finite-element model. Proc IMechE Part F: J Rail and Rapid Transit, doi: 10.1177 / 0954409715569558, 2015.

Claims

1. Mobile plant system (100) for dynamic characterization of railway superstructures (200) elements characterized by the fact that it comprises:

an exciter device (1) linkable to a railway superstructure (200), in which the exciter device (1) in turn comprises vibration and load generating means (20) arranged on a bench (30) which is linkable by at least one way (201) through at least some means of coupling to the superstructure as a support (40); Y

data processing means (50) in communication with a load sensing means (6) and vibration acceleration sensing means (7), in which the load sensing means (6) are arranged in at least one support (40) and the vibration acceleration sensor means (6) are capable of positioning at least one component of the superstructure (200).

2. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to claim 1, characterized in that the vibration and load generating means (20) comprise at least one pair of disks ( 21, 22) counter-rotating mass arranged unbalanced with respect to their respective axes of rotation, in which the disks (21, 22) are driven by at least one driving unit (23), in which a first disk ( 21) is linked to the drive unit (23) through a power transmission (27) or primary, and the second disk (22) is linked to the drive unit (23) by a synchronized (24) or secondary transmission .

3. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to the preceding claim, characterized in that in the pair of disks (21, 22) they comprise two holes, recesses or protuberances (26 ) positioned eccentrically, and capable of carrying inserts (25) of determined masses.

4. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to any one of the preceding claims, characterized in that the vibration and load generating means (20) are configured to vary their frequency .

5. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to any one of the preceding claims, characterized in that the load sensing means (6) comprise a load cell.

6. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to any one of the preceding claims, characterized in that the vibration acceleration sensor means (7) comprise a plurality of positionable accelerometers in a superstructure (200) with a ballad track, such that at least one accelerometer is capable of being positioned in a rail fastener (202), another between a pair of sleepers (203), another in a sleeper (203) and another in a land adjacent to a ballast (204).

7. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to any one of the preceding claims, characterized in that the vibration acceleration sensor means (7) comprise a plurality of positionable accelerometers in a plate track or floating slab superstructure (200) in which a track (201) is subject to a plurality of blocks arranged on at least one plate, such that at least one accelerometer is capable of being positioned in a clamp of the rail (202), another between blocks, another in a block, another in the plate and another in a land adjacent to the plate.

8. Mobile plant system (100) for dynamic characterization of elements of railway superstructures (200) according to any one of the preceding claims, characterized in that the coupling means to the structure as a support (40) are mobile respect the bench (30).

9. Method for dynamic characterization of elements of railway superstructures (200) characterized by the fact that it comprises the steps of:

a) generate at least one tonal excitation and a load (F3) on an element of the superstructure,

b) measure the load (F3) or dynamic sinusoidal force applied to at least one element of the superstructure (200), and the acceleration of the vibrations induced in at least one element of the superstructure, c) reverse an analytical or numerical superstructure model (200) based on the acceleration measured in step b).

10. Method for dynamic characterization of elements of railway superstructures (200) according to the preceding claim, characterized in that the analytical or numerical model of the superstructure (200) is determined according to the following formula:

Ü (x _u ) = (p, F (x _f )), Formula 1 in which Ü (x _u ) is the vibration acceleration in a given frequency domain for at least one evaluation position x _u at a point in the superstructure (200),

Φ is the operator that represents the analytical or numerical model,

p is at least one input variable of the analytical or numerical model and

F (x _f ) is at least one dynamic sinusoidal force in the determined frequency domain and applied over at least a certain excitation position x _f in the superstructure (200).

11. Method for dynamic characterization of elements of railway superstructures (200) according to the preceding claim, characterized in that the variable p is at least dynamic stiffness or damping.

12. Method for dynamic characterization of elements of railway superstructures (200) according to any one of claims 9-11, characterized in that at step c) at least one parameter p of Formula 1 is calculated, minimizing a part real:

Re (Ü _theo (x _u ) - Ü _exp (x _u )),

and an imaginary part:

lm (Ü _theo (x _u ) - Ü _exp (x _u )), considering that F _theo (x _f ) = F _exp (x _f ),

in which

F _theo (x _f ) is a previously determined sinusoidal dynamic force, Ü _exp (x _u ) is a vibration acceleration measured experimentally in a given frequency domain for at least one evaluation position x _u at a point of the superstructure (200),

^F exp ( ^x _f ) ^{is a} dynamic sinusoidal force measured experimentally in the determined frequency domain and applied over at least a certain excitation position x _f in the superstructure (200).

13. Method for dynamic characterization of elements of railway superstructures (200) according to any one of claims 9-12, characterized in that in stages b) and b), the element of the superstructure (200) to which apply the face is at least one way (201).

14. Method for dynamic characterization of elements of railway superstructures (200) according to any one of claims 9-13, characterized in that the model Φ is of two-dimensional or three-dimensional type.

15. Method for dynamic characterization of elements of railway superstructures (200) according to any one of claims 9-14, characterized in that the tonal excitation of step a) occurs in a frequency range between 1 and 80 Hz .

16. Method for dynamic characterization of elements of railway superstructures (200) according to any one of claims 9-14, characterized in that the tonal excitation of step a) occurs in a frequency range between 10 and 80 Hz .

17. Computer program comprising program instructions for making a computer system perform the method for dynamic characterization of railway superstructures (200) according to any one of claims 9-16.

18. Computer program according to the preceding claim that is stored in storage media.

19. Computer program according to claim 17 which is carried by a carrier signal.