ES2671913B1 - DESIGN PROCEDURE OF A SYSTEM OF VIA IN PLATE AND SYSTEM OF VIA IN PLATE DESIGNED - Google Patents

Description

DESIGN PROCEDURE OF A PLATE TRAY SYSTEM

AND DESIGNED ROOF SYSTEM

DESCRIPTION

Object of the invention

The present invention relates to a method of designing an on-track system, which from a numerical model validates the design of the components of the track on the plate, avoiding the need to build and test the plate with a train. real such as occurs in the construction of railway platforms with track systems on plate., is also the object of the invention a system of track in plate designed with the exposed procedure. The invention is applicable in the field of construction, specifically in the field of railway construction.

Technical problem to solve and background of the invention

In railway construction, the track in plate is a type of platform that guarantees high quality and geometric adjustment capacity. The need for maintenance decreases with this solution, compared to the ballast.

The installation of the plate is made without ballast, on a continuous concrete slab that transmits to the platform uniformly distributed stresses, with an intermediate layer of cement mortar and asphalt.

So far, for the verification of the behavior of a solution with track on plate, it was necessary to carry out real scale tests and test sections with the passage of real trains to check the dimensioning carried out.

By means of the design procedure object of the invention, a track is obtained on the plate whose response to the demands to which it will be subjected during the useful life of the track is known in advance that it is capable of supporting them, avoiding the need to manufacture a section. of track in which the components of the track system on the plate under study are used, and avoiding the need to check the response of said plate to the stresses produced by real trains in a trial and error process, reducing the time spent in the development of a track in plate and therefore the money necessary for new developments.

Description of the invention

The present invention relates to a method of designing an on-track system, where the track system comprises the following components: a rail, a fixing, a concrete plate, a cement mortar and asphalt cushion, a continuous concrete slab placed on a ground; all these components having a geometry and parameters that define them, where at least one component is designed to be chosen between the fixing, the concrete slab, the cement and asphalt mortar cushion and the continuous concrete slab.

The procedure object of the invention comprises the following steps:

- establish a dynamic load of a train under study to be supported by the on-board track, represented as a complete pulse,

- establish a first geometry of the track components on the plate, - carry out a modal analysis of the track system on the plate,

- perform a transient analysis of the track system on board,

- perform a fatigue calculation in compression on the track system on a plate by means of a previously established numerical model, which comprises the following steps:

- model each component of the track system in the numerical model, introducing the first geometry and first values of the parameters of each component,

- simulate the dynamic load to be supported by the on-board track system of a complete train, represented by a full pulse corresponding to the dynamic load applied at each moment,

- calculate the damage generated in a node of the concrete plate,

- repeat the calculation of the damage on all the nodes of the board,

- compose a damage map of the numerical model of the concrete plate depicting the damage in each node on a map, and

- give the design of the track system on board as correct when the damage on any of the nodes exceeds a value of 1.

The steps of establishing a dynamic load of a train object of study to be supported by the track in plate, represented as a complete pulse and of establishing a first geometry of the components of the track in plate, can be carried out in a way simultaneous or reversing the order.

In the design procedure of an on-board track system object of the invention, the step of calculating the damage generated in a node is carried out with the following procedure:

- extract the history of a main compression stress in that node of the complete pulse corresponding to the dynamic load applied at each instant in the node,

- count the fatigue cycles of the main compression tension by means of a known algorithm, in which the cycles counted by voltage levels are grouped and the cycles are added with the same voltage level,

- calculate the number of cycles that the concrete is able to resist for each voltage level by means of a known formulation,

- obtain the damage in the node for each voltage level by dividing the number of fatigue cycles of the main compressive tension counted between the number of cycles that the concrete is able to resist for each voltage level, - find the total damage in that node adding the damage for each voltage level.

In the design process of a track system object of the invention to calculate the number of cycles that is able to resist the concrete for each level of tension, a formulation is used to choose between: Code Model 2010, model proposed by Castillo et al, proposal by Hsu et al and current regulations in the calculation model.

The method of designing an on-board track system object of the invention when the damage in any node of the board exceeds a value of 1, comprises the additional steps of:

- modify at least one value to choose between the first geometry and the parameters that define the rail, the fixation, the concrete slab, the cement mortar and asphalt cushion, the continuous concrete slab,

- re-perform the fatigue calculation in compression by means of a previously established numerical model,

- compose a damage map of the numerical model of the concrete plate depicting the damage in each node on a map, and

- give the design of the track system on board as correct when the damage in none of the nodes exceeds a value of 1.

In the step of modifying at least one value to choose between the geometry and the parameters that define the fixation, the concrete slab, the cement and asphalt mortar cushion and the continuous concrete slab of the design procedure of a track system In the plate object of the invention, a thickness of the concrete plate is first modified.

In the step of modifying at least one value to choose between the geometry and the parameters that define the fixation, the concrete slab, the cement and asphalt mortar cushion and the continuous concrete slab of the design procedure of a track system In the plate object of the invention, at least one value to be chosen is chosen between a compression resistance, an elastic modulus and a Poisson's coefficient of the parameters that define the concrete plate.

In the design process of a track system object of the invention the dynamic load to be supported by the track system from a target train represented by a complete pulse, is simulated from a pulse corresponding to a bogie known of any train, and includes the following steps:

- perform a temporary scaling of the known bogie pulse, by changing a base of times of the known train to a base of times of the target train, obtaining a temporarily scaled pulse,

- compose a pulse of a temporarily scaled train corresponding to the target train, repeating the temporarily scaled pulse for the bogies of cars and locomotives of the target train,

- scaling the amplitude of the pulse of a temporarily scaled train corresponding to the target train, multiplying the pulse of a temporarily scaled train corresponding to the target train by a factor,

- obtain a complete pulse corresponding to the entire train, to adapt the complete pulse to the total weight of the entire train.

In the design process of a track system object of the invention, the dynamic load to be supported by the track system on board from a target train represented by a complete pulse, is obtained from real data, and It comprises the following steps:

- collect data from real train records, represented as real pulses, and for each actual pulse,

- perform a temporary scaling of the actual pulse, by changing a base of times of the known train to a base of times of the target train,

- perform an amplitude scaling, multiplying the temporarily scaled pulse by a factor obtaining a complete pulse corresponding to the target train,

- apply the Fourier transform by decomposing the real pulse into harmonics, - find the average spectrum of the signals,

- apply anti-Fourier transform.

In the method of designing a track system on the plate object of the invention, performing the modal analysis comprises calculating the proper modes of vibration and natural frequencies associated with each vibration mode.

In the design process of a track system object of the invention, the stage of finding the accumulated damage for each node is made by the Palmgren-Miner law that adds up the damage obtained in the cycles for each voltage level.

Another object of the invention is a plate track system that has been designed by the method disclosed in any of the preceding claims.

Description of the figures

To complete the description and in order to help a better understanding of the characteristics of the invention, this descriptive report is accompanied, as an integral part thereof, a set of drawings in which illustrative and non-limiting, the following:

Figure 1 shows a block diagram with the steps of the design procedure of an on-board track system.

Figure 2 shows a block diagram with the steps for producing a complete pulse of a train object of study from a known pulse of a bogie.

Figure 3 shows a block diagram with the steps to elaborate a complete pulse of a train object of study from a real pulse of a train.

Figure 4 shows a block diagram with the fatigue calculation steps in compression by means of a numerical model.

Figure 5 shows a plan view of the preferred embodiment of the concrete plate used in the track system on the plate object of design with the process object of the invention.

Figure 6 shows the modeling of the symmetrical half of the concrete slab, as well as the corresponding fixings.

Figure 7 shows a cross section of lane modeling.

Figure 8 shows the modeling of the symmetrical half of the system, the track in the design object, including the rail, the fixings, the concrete slab, the cement and asphalt mortar cushion and the continuous concrete slab.

Figure 9 shows a modeling of the symmetrical half of the track system in the finite element model including the terrain in addition to the elements of Figure 8.

Figure 10 shows the generic configuration of a Type A Universal Dynamic Train.

Figure 11 shows the pulse corresponding to a known bogie of any train.

Figure 12 shows the pulse of train type A showing on the x axis the time in seconds and on the axis and the load in kN.

Figure 13 shows the pulse of Figure 12 in harmonics showing on the x-axis the time in seconds and on the axis and the frequency in Hz.

Figure 14 shows the evolution in time of the maximum equivalent voltage on the central plate after applying the pulse of figure 12 showing on the x axis the time in seconds and on the axis and the equivalent voltage in MPa.

Figure 15 shows the evolution over time of the seat on the central plate after applying the pulse of figure 12 showing on the x-axis the time in seconds and on the axis and the seat in mm.

Figure 16 shows the complete pulse of the load calculated from real data records for the train AVES103 showing on the x-axis the time in seconds and on the axis and the load in kN.

Figure 17 represents the distribution of the equivalent voltage expressed in MPa in the central plate for the instant 0.224 seconds counted since the train type A reaches the first plate, the different values of the equivalent voltage are shown with different screenings.

Figure 18 shows the seat of the central plate at the instant 0.224 seconds counted since the train type A arrives at the first plate, the different values of the seat are shown with different screenings.

Figure 19 represents the history of amplified voltages by a factor of 5, for the most unfavorable node of the central plate, highlighting with a thicker line the compression tension.

Figure 20 shows the map of fatigue damage in the central plate amplifying the load of the train type A by a factor of 5, the different damage values are shown with different screens.

The references that are reflected in the figures correspond to the following elements:

1. - track system,

2. - rail,

3. - fixation

4. - concrete plate,

5. - Cement and asphalt mortar cushion,

6. - continuous concrete slab,

7. - land,

8. - establish a dynamic load of a train under study to be supported by the on-board track,

9. - Establish a first geometry of the components of the track on the plate, 10. -Make a modal analysis,

11. -To carry out a transitory analysis,

12.-Carry out a calculation to fatigue in compression on the system of track in plate by means of a numerical model,

13. -modeling each component of the track system,

14. - simulate the dynamic load to be supported by the track system of a complete train, represented by a complete pulse,

15. -calculate the damage generated in a node,

16.-repeat the calculation of the damage on all the nodes of the board,

17. -compose a damage map of the numerical model,

18. -give the design of the track system on board as correct when the damage in any of the nodes exceeds a value of 1,

19. -extract the history of a main compression tension in that node, 20. -count the fatigue cycles of the main compression tension,

21. -calculate the number of cycles that is able to resist the concrete for each voltage level,

22.-get the damage in the node for each voltage level,

23.-find the total damage in that node,

24.-modify at least one value,

25.-thickness of the concrete slab,

26.-pulse corresponding to a known bogie,

27.-Make a temporary escalation,

28. -complete a pulse of a temporarily scaled train corresponding to the target train,

29. -Make an escalation in amplitude,

30. - obtain a complete pulse corresponding to the complete train,

31. -collect data from real train records,

32.-Temporal scaling of the real pulse,

33. - apply the Fourier transform,

34.-Find average spectrum of signals,

35. -Apply Fourier Transform,

36. -central lightening;

37. -bocado,

38.-full pulse,

39.-car length,

40. - Distance between axes,

41. -pulson in harmonics,

42.-equivalent voltage,

43. - I sit, and

44. -damage.

Description of an embodiment of the invention

Next, a description of an embodiment of the invention is presented, referring to the references of the figures.

A track system (1) is formed by the following elements, described from the area of contact with the train to the furthest part of the train:

- lane (2) UIC-60 (observable modeling in figure 7),

- fixation (3),

- concrete plate (4),

- Cement and asphalt mortar cushion (5),

- continuous concrete slab (6), and

- land (7).

The procedure object of the invention deals with, from a preliminary design of a track system on board (1) defined by a first geometry and first values of the parameters of the components of the track system on board (1), check the behavior of said preliminary design of a track system (1) against project loads, especially fatigue behavior in compression, said behavior is verified from a numerical model developed for the procedure object of the invention, which provides a damage map (44) of the prediction of the behavior of the on-track system (1), through which the first geometry and the first values of the parameters of the components of the system are accepted. via plate (1).

In the numerical model it is necessary to enter values of the parameters of the track system components (1). The values of these parameters are well known through experimental tests or extracted from specialized literature. These parameters are: resistance to compression fc, elastic modulus E, Poisson coefficient v, density p and fraction of critical damping

Firstly, it is necessary to know the dimensions of the components of the track system (1) from which its behavior is to be tested in order to model each component in the numerical model of the track system (13). For the preferred embodiment of the invention, a rectangular concrete plate geometry (4) having a central lightening (36) and two semicircular mouths (37) located in the center of the smaller sides of the plate has been chosen. concrete (4) (this geometry can be seen in figure 5), said mouths (37) correspond to a cylindrical concrete stop (not shown) existing between the concrete plates (4) that absorbs the lateral and longitudinal forces of the concrete plates (4).

The dimensions of the concrete plate (4) chosen in the preferred embodiment of the invention are: length 5.13 meters, width 2.50 meters and thickness (25) 0.22 meters, and the dimensions of the central lightening (36) they are 2.99 meters long, 0.79 meters wide and 0.22 meters thick.

It is necessary to know the optimum number of concrete plates (4) that are going to be considered in order to obtain a representative behavior of the superstructure of the track system (1). For the preferred embodiment of the invention, three concrete plates (4) joined by cylindrical stops are considered, ie the length of the numerical model is 15.53 meters, which corresponds to three concrete plates (4) separated by seven centimeters (5.13 + 0.07 + 5.13 + 0.07 + 5.13 meters).

In the numerical model used in the procedure object of the invention, a calculation program based on the finite element method is used. The calculation of the numerical model is done in an elastic regime.

The geometry of the concrete plate (4) of the track system in plate (1) object of design, in the preferred embodiment of the invention, presents symmetry with respect to an axis main which represents a simplification to be taken into account in the numerical model because only the symmetrical half of the concrete plate is modeled (4). The fact that the modeling of the concrete plate (4) is made with only half of the concrete plate (4) is a saving in the calculation time of the numerical model.

With this first geometry of the track system components, two analyzes are carried out:

- A modal analysis (10): calculates the own modes of vibration and the natural frequencies associated with each mode.

- A transient analysis (11): calculates the response of the concrete plate (4) to a transient dynamic load.

The modal analysis (10) predicts the dynamic behavior of the track system (1), determining the natural frequencies and the associated vibration modes, considering that structures have as many modes of vibration as degrees of freedom. The determination of the natural frequencies and the vibration modes associated with them is done to verify that the track (1) does not come into resonance according to the dimensioning carried out, that is, that the combination of the vibration modes considered makes the load applied is magnified and consequently the damage (44) produced to the track system (1) is also magnified.

Said modal analysis (10) is solved by means of the equation:

[M] ü [K] u = 0

where [M] is the mass matrix, ü is the acceleration, [K] is the stiffness matrix, and u is the displacement.

The modes of vibration considered in the numerical model are:

- those produced at low frequency,

- those with a specific frequency equal to the frequency of the load spectrum to which the structure is subjected,

- those in which the point of application of the load and the most unfavorable zone of the modal analysis coincides spatially (10),

- those in which the sense of vibration characteristic of the structure is in phase with the applied load.

The transient analysis (11) is a dynamic calculation by which the linear response of a structure to variable loads over time is calculated, so it needs a data entry corresponding to the load applied at each instant of time.

To perform the transient analysis (11) the equation is used:

[M] ü [C] ú [K] u = F {t )

In the above equation, the term [M] represents the inertia of the system, [C] the damping that opposes the velocity and [K] the rigidity of the system; ü the acceleration, ú the speed and u the displacement.

Damping is known as the ability of a system or body to dissipate energy. The damping in the track in plate translates into the ability of the concrete to dissipate the energy provided by the acting load of the train.

In the transient analysis (11), given that the damping matrix is a difficult element to determine experimentally, it is hypothesized that the damping matrix is a linear combination of the stiffness and mass matrices, thus said matrix of Damping is expressed as:

In the above equation the multiplier of the mass matrix a is considered negligible, assuming that the structure dampens much where it is very rigid, the degree of damping is expressed as a function of the critical damping fraction of the material and the frequency (f) of greater amplitude of the applied load.

The actions applied on the structure at very low frequency produce very low speeds and accelerations compared to relatively large displacements, that is, the system behaves as if it were static. As the frequency of the actions increases, the term of the damping becomes important, but at very high frequencies the value becomes very low, and therefore the damping term of the general equation of the dynamics, loses a lot of weight in favor of the term that represents inertia.

Introducing in the numerical model the previous data of the load at each moment and performing the aforementioned transient analysis (11), the evolution of the maximum equivalent voltage (42) is obtained, in the central plate (observable in figure 14). Figure 15 represents the evolution in time of the seat (43) on the central concrete plate (4) after applying the full pulse (38). These maximum values correspond to different nodes of the concrete plate (4) central according to the moment. Thus the maximum value of the equivalent voltage (42) occurs at 0.224 s and the maximum seat (43) at 3.732 s since the train reaches the first plate (of the three plates that have been considered for the numerical model). The maximum equivalent voltage (42) of 0.64 MPa is reached at 0.224 s around the inner corner of the concrete plate (4).

Figures 17 and 18 represent, respectively, the distribution of the equivalent tension (42) at the instant corresponding to 0.224 s, and the seat (43) at that same instant, for the half of the concrete plate (4) modeled on the numerical model.

Figure 6 shows the modeling of the symmetrical half of one of the concrete slabs (4) with eight fixings (3) spaced 0.65 m apart from the center of gravity of the fixings (3).

The lane (2) is modeled with a uniaxial element of two nodes with six degrees of freedom in each node, (translation and rotation in the directions of the three axes). In figure 7 a cross section of the lane modeling (2) can be observed.

To introduce the concrete plate (4) in the numerical model, a volumetric element of 8 nodes with three degrees of freedom per node (translation in the three axes) is used. To enter in the numerical model the values of the parameters of the concrete of the concrete plate (4) the values that correspond to a concrete of standard resistance have been used, and with respect to the elastic modulus, it is considered the one that usually corresponds to reinforced concrete.

To introduce the fixation (3) in the numerical model, a simplification has been made, and it is introduced using also the volumetric element of 8 nodes with three degrees of freedom per node (translation in the three axes), simulating the fixation (3) with an approximate length of 0.35 meters. The fixing (3) is represented by a deformable solid connecting the rail (2) with the surface of the concrete plate (4), in which the movement between the fixing (3) and the concrete plate (4) is restricted. ) to the movement of a rigid solid.

As already stated in the track system (1) under the concrete plate (4) is a cushion of cement mortar and asphalt (5), for the introduction in the numerical model said cement mortar cushion and asphalt (5) has been modeled with the volumetric element of 8 nodes with three degrees of freedom per node (translation in the three axes) already used. In the preferred embodiment of the track system (1) the cement mortar and asphalt cushion (5) has a rectangular shape and is distributed on both sides of the central lightening (36) of the concrete plate (4). The dimensions of the cement and asphalt mortar cushion (5) in the preferred embodiment of the plate are: length 5.13 meters, width 0.85 meters and thickness 0.10 meters.

Likewise, below the cement and asphalt mortar cushion (5) there is a continuous concrete slab (6) along the three concrete slabs (4) considered in the numerical model, which gives a total length of continuous concrete slab (6) of 15.53 meters. For the introduction in the numerical model, the continuous concrete slab (6) is modeled with the volumetric element of 8 nodes with three degrees of freedom per node already used (translation in the three axes). The complete geometry of the numerical model incorporating the concrete plate (4), the cement mortar and asphalt cushion (5), the continuous concrete slab (6), the fasteners (3) and the rail (2) can be seen in figure 8.

Under the continuous concrete slab (6), there is the ground (7) on which rests the rest of the components of the track system (1) indicated in the previous paragraph. This land (7), for its introduction in the numerical model, has been modeled in different layers using the same volumetric element of 8 nodes with three degrees of freedom per node (translation in the three axes).

It is necessary to determine to what depth the terrain (14) must be modeled in the numerical model. To determine this depth it is necessary to calculate to what extent the loads applied on the concrete plate (4) object of the invention affect the ground. For this calculation it has been established that the limit depth is the depth at which a load applied to the surface produces a virtually nil and constant displacement.

For the above calculation, the increase in effort (ov) in the ground (14) produced by a vertical point load as a function of the depth is calculated by means of the equation:

3 Qz2

ov _5

2 n (r2 z2) z

being:

- Q: load applied to the ground;

- r: radial distance to the calculated point (in m);

- z: soil depth (in m).

Using this expression and taking a load Q of 75kN (the vertical point load), it is obtained that at 4.5 meters depth the vertical voltage av is almost negligible, so according to calculations a minimum thickness of 4 must be considered, 5 meters, to be on the security side, in the numerical model of the preferred embodiment of the invention a ground thickness (7) equal to 6.3 meters is modeled.

In the conditions of contour, the corresponding restrictions are imposed on the symmetry of the concrete slab (4) and the rest of the components, and the restrictions of the sides of the continuous concrete slab (6), of the ground (7). With respect to the concrete plate (4), the movement in the transverse axis of the model area in contact with the plane of symmetry, as well as the cushion of cement mortar and asphalt (5), of the floor is prevented ( 6) and the land (7). Regarding the ground (7), the continuous concrete slab (6) and the rail (2) prevent the longitudinal movement in both ends of the numerical model.

Figure 9 shows the complete modeling of the symmetrical half of the components of the track system (1) including also the ground (7) on which the continuous concrete slab (6) rests.

It is also necessary to know the dynamic load to which the on-track system will be subjected (1), in this case it is the dynamic load generated by a train considering all the cars and locomotives of that train.

The procedure object of the invention simulates the dynamic load of a train object of study to be supported by the track system on board by means of a complete pulse (14) corresponding to the dynamic load applied at each instant.

To represent the dynamic load applied as a function of time, the procedure object of the invention uses a complete pulse (38), said complete pulse (38) corresponds to the pulse that produces the greatest damage (44) in the concrete plate ( 4).

To obtain this complete pulse (38) it is necessary to obtain the density function of the frequency spectrum or spectrum of the signal, which is a positive and real function of variable frequency, associated with a stochastic process or a deterministic function in time that helps identify periodicities. This function shows the amplitude of the vibrations with the frequency.

The complete pulse (38) can be constructed from real data collected in a section of the track (represented as a real pulse of a train), or from a pulse of a known bogie (26).

In the embodiment in which a complete pulse (38) of an actual train is constructed from the pulse of a known bogie (26), it is considered a train that appears in the Railway Actions and Bridges Instruction (IAPF), as Universal Dynamic Train A.

The Universal Dynamic Train A (observable in figure 10) is made up of two locomotives and ten cars, with an axle weight of 187 kN and 120 kN respectively, which makes a total weight of 6,296 kN. The total length of the train is 295.4 m.

Returning to figure 10, the length of each car (39) in meters is 26.1 meters and of each locomotive is 17.2 meters, while the wheelbase (40) is the same for the locomotive and the cars, and equal to 3 meters. This circulates at a speed of 300 km / h.

To construct the complete pulse (38) of the Universal Dynamic Train Type A, a temporary scaling (27) and an amplitude scaling (29) are applied to the pulse of the known bogie (26) (observable in figure 11).

The temporary scaling (27), is done because the wheelbase of the bogies of the Universal Dynamic Train A does not match, from which we want to know the complete pulse (38) and the wheelbase of the train from which the pulse of the known bogie comes ( 26) (when belonging to any train), so we must change the time base of the pulse of the known bogie (26) and adapt it to the Universal Dynamic Train Type A from which we want to know the complete pulse (38).

In a simplified way, knowing the lengths and distances between the axes of the locomotives and the cars that make up the Universal Type A Dynamic Train, and the speed at which they circulate, the complete pulse (38) of a train can be constructed from the pulse data of the known bogie (26), performing the temporary scaling of the known bogie pulse (26) and repeating the aforementioned pulse already scaled for each bogie of the train, both for the locomotives and for the cars. Subsequently, all the temporarily scaled pulses corresponding to the two locomotives and the ten cars that make up the Universal Dynamic Train Type A are juxtaposed, and a temporarily scaled pulse is obtained for a complete train that has the same shape as the one that has the pulse of the Train. Dynamic Universal Type A, but has a magnitude not commensurate with the weight of the Universal Dynamic Train Type A. To adapt the temporarily scaled pulse of a complete train, the weight of the Universal Dynamic Train Type A, amplitude scaling is performed (29) .

Said amplitude scaling (29) consists in finding a factor by which to multiply the temporarily scaled pulse of a complete train that guarantees that the pulse obtained with the scaling in time corresponds to the weight of that train.

The signal spectrum is obtained by processing the load record of the train (figure 12) by the application of the Fourier transform in the time domain, the pulse is decomposed into harmonics (41) that occur at different frequencies (observable in Figure 13), where each harmonic is identified with certain parts of the train. In Figure 13 it can be seen that the amplitude of the harmonics decreases progressively, due to the damping of the structure itself.

The other option to build the complete pulse (38) of a train is to do it from the real signal of a train obtained in a register of real signals

The registration of real signals, in the preferred embodiment of the invention, comes from a train with the following characteristics: total length 200.84 meters with 8 cars (with two bogies per car and two axles per bogie) and total mass 484.6 tons.

This recording of real signals requires a treatment to adapt it to the train object of study, for it, the first axis of all the signals is matched to have equivalent measurements, then the temporary scaling of the real pulse (32) is made, so that the base of the times is changed so that the instant that elapses between the first and the last axis coincides with the time that would pass for a train circulating at a speed of calculation (in this case 300 km / h have been estimated), taking into account the length of the train; Then the amplitude scaling is carried out (29), in which a factor is sought by which to multiply the temporarily scaled pulse, guaranteeing that the pulse obtained in the amplitude scaling corresponds to the total weight of the train, thus obtaining the pulse complete (38) of a train.

Once the double scaling has been carried out (32, 29), it is a matter of obtaining a mean signal, for which, applying the Fourier transform (33) in the time domain, the spectrum is passed on in frequency by decomposing the pulse in harmonics that occur at different frequencies, and there is an average spectrum of all the signals (34), to apply an anti-Fourier transform (35) back to the original signal.

In Figure 16 the load pulse of this real train is reflected from the procedure described above for a speed of 300 km / h.

In the procedure object of the invention, fatigue calculation in compression is performed by means of the numerical model previously established (12), on the concrete plate (4), so that the damage (44) generated by the load cycles produced is obtained. To calculate the aforementioned damage (44) in a node, the following steps are followed:

- extract the history of tensions in the direction of the maximum compression principal voltage detected in the transient analysis (11) at that node (19) of the complete pulse (38),

- counting the fatigue cycles of the main compression tension (20) by means of a known algorithm, in which the cycles counted by voltage levels are grouped and the cycles are added with the same voltage level,

- calculate the number of cycles that the concrete is able to resist for each voltage level (21) by means of a known formulation,

- obtain the damage (44) in the node for each voltage level (22) by dividing the number of fatigue cycles of the main compressive tension counted by the number of cycles that the concrete is able to resist for each voltage level,

- find the total damage (44) in that node (23) by adding the damage (44) for each voltage level.

Figure 19 represents the history of voltages for one of the nodes of the board. In it we can see: the main tensions, Sigma1, Sigma2 and Sigma3, the compression stress highlighted with thicker line, SigmaC, and the equivalent voltage (42), Seqv.

The voltage values shown in Figure 19 have been amplified by a factor of 5 to obtain significant damage values (44).

To count the fatigue cycles of the main compression tension (20) the algorithm developed by Downing and Socie is applied. Compression tension cycles, Sigma C, are counted in the voltage-time curve of Figure 19, with the aim of finding and counting the closed cycles. In summary, the procedure is as follows:

- a point is assigned to each value of the compression tension.

- each cycle of figure 19 is constituted by three of these points.

- to form a closed cycle the following condition must be given: the voltage value of the third point must be greater than or equal to that of the first, otherwise we continue with the next point until that condition is met. - when a cycle is formed, these points are excluded and the counting of the adjacent points continues.

For the calculation of the damage (44) and the estimation of the life in fatigue for a spectrum of load levels for cycles of different amplitude, the Palmgren-Miner law is used in the process object of the invention.

According to the law of Palmgren-Miner, the damage (44) exerted by a single cycle is inversely proportional to the number of cycles of the same amplitude that can cause the break, applying the equation exposed below:

where Di is the damage (44) in fatigue for a certain level and amplitude of the voltage, nor is the number of voltage cycles that we have counted by applying for that level of voltage and amplitude, and Ni is the number of cycles that produce the break for that same level.

This formulation makes it possible to estimate the accumulated damage (44) by applying cycles of different amplitudes on the plate. According to this formulation, the break occurs when D = 1.

Returning to the example, in the aforementioned figure 19, the history of tension is represented. Using this curve the cycles are counted following the algorithm of Downing and Socie and accumulated in a matrix. For those voltage levels, the number of cycles that it resists is calculated using the Model Code (Model Code 2010).

Finally, the damage (44) is obtained by dividing the number of cycles counted by the number of cycles that resist for each voltage level. Adding all the damage values (44) of the previous matrix, we obtain the total damage (44) in that node, since the total damage (44) following the Palmgren-Miner law is calculated by adding the damage (44) caused by cycles with variable voltage amplitudes, such as the history of voltages caused by the loading of a train.

Repeating this procedure for all the nodes of the plate, the damage map (44) is obtained by fatigue. Figure 20 shows the damage map (44) of the central plate applying the load of the train type A, multiplied by a dynamic amplification factor to take into account imperfections in the rail (2) or in the rolling stock. As can be seen in figure 20, the areas with the greatest damage (44) are below the central restraints (3), especially in the third and fourth.

To consider the signal that produces the most damage (44), a set of random phases are generated for each of the frequencies in which the pulse corresponding to the whole train has been decomposed and then the Fourier antitransformed is applied to obtain a signal that is enter the model. This signal is the one used to

The process of generating random signals is repeated and the damage (44) produced by each of them is calculated.

In the procedure, the signal which produces a greater damage (44) is chosen, and which in the preferred embodiment of the invention corresponds to the damage percentile (44) of 95%, then we have a probability of obtaining damage (44) greater than 5%.

In the procedure object of the invention when the damage (44) calculated in all the nodes, is less than 1, the on-board track system, with the dimensions and values of the parameters that define the different components, is considered valid.

When the damage (44) calculated in some node exceeds the value of 1, it is necessary to modify some very dimensional parameter, or some numerical value of the components of the track system (1) object of the design procedure.

In the latter case, in the process object of the invention it is possible to modify at least one value (24) to be chosen between the first geometry and the parameters defining the rail (2), the fixing (3), the concrete plate (4), the cement mortar and asphalt cushion (5), the continuous concrete slab (6), or modify a thickness (25) of the concrete plate (4).

Then, in the procedure object of the invention, the compression fatigue calculation is performed again by means of a previously established numerical model (12), the damage map (44) of the numerical model (17) of the plate is made up concrete (4) represented the damage (44) in each node in a map, and the design of the track system is given as correct when the damage (44) in any of the nodes exceeds a value of 1 (18) , or if the damage (44) were again greater than 1, one of the parameters or values exposed in this same paragraph is modified again, until the design of the track system is given as correct when the damage (44 ) in none of the nodes exceeds a value of 1 (18).

The method of designing a track system (1) here exposed can be used to design a track system in plate (1) in which the concrete plate (4) is prefabricated or manufactured in situ in an indistinct manner, since it requires data that are known or can be known about the proposed design for its verification and / or modification.

Finally, the object of the invention is a track system (1) designed with the design procedure explained above.

The invention should not be limited to the particular embodiment described herein. Experts in the field can develop other embodiments in view of the description herein made. Accordingly, the scope of the invention is defined by the following claims.

Claims (11)

A method for designing a track system (1) where the track system (1) comprises the following components: a rail (2), a fixing (3), a concrete plate (4), a cement and asphalt mortar cushion (5), a continuous concrete slab (6) located on a ground (7); all these components having a geometry and parameters that define them, where at least one component to be chosen is designed between the fixing (3), the concrete plate (4), the cement mortar cushion and asphalt (5) and the continuous concrete slab (6), characterized in that the method comprises the following steps: - establish a dynamic load of a train under study to be supported by the track (8), - establish a first geometry of the track components on the plate (9), - perform a modal analysis (10) of the track system on the plate (1), - carry out a transient analysis (11) of the track system (1), - performing a compression fatigue calculation on the track system (1) by means of a previously established numerical model (12), which comprises the following steps: - modeling (13) each component of the track system (1) in the numerical model, introducing the first geometry and first values of the parameters of each component, - simulate the dynamic load of a train object of study to be supported by the track system (1) by means of a complete pulse (14) corresponding to the dynamic load applied at each instant, - calculate the damage (44) generated in a node (15) of the concrete plate (4), - repeat the calculation of the damage (44) on all the nodes of the plate (16), - compose a damage map of the numerical model (17) of the concrete plate (4) representing the damage in each node on a map, Y - give the design of the track system in plate by correct when the damage (44) in any of the nodes exceeds a value of 1 (18). 2. Method for designing a track system (1) according to claim 1, characterized in that the damage (44) generated in a node (15) is calculated with the following procedure: - extract the history of tensions in the direction of the maximum compression principal voltage detected in the transient analysis (11) at that node (19) of the complete pulse (38), - counting the fatigue cycles of the main compression tension (20) by means of a known algorithm, in which the cycles counted by voltage levels are grouped and the cycles are added with the same voltage level, - calculate the number of cycles that the concrete is able to resist for each voltage level (21) by means of a known formulation, - obtain the damage (44) in the node for each voltage level (22) by dividing the number of cycles of fatigue of the main compressive tension counted between the number of cycles that is able to resist the concrete for each voltage level, - find the total damage (44) in that node (23) by adding the damage (44) for each voltage level. 3. Method for designing a track system (1) according to claim 2, characterized in that to calculate the number of cycles that the concrete is able to resist for each voltage level (21), a formulation is used to choose between : Code Model 2010, model proposed by Castillo et al, proposal of Hsu et al and the regulations in force at the time of calculation. 4. Procedure for designing an on-board track system (1) according to any of the preceding claims, characterized in that when the damage (44) in any node of the board exceeds a value of 1, it comprises the additional steps of: - modifying at least one value (24) to be chosen between the first geometry and the parameters defining the rail (2), the fixing (3), the concrete plate (4), the cement mortar cushion and asphalt (5) ), the continuous concrete slab (6), - re-perform the fatigue calculation in compression by means of a numerical model (12) previously established, - compose a damage map (44) of the numerical model (17) of the concrete plate (4) representing the damage (44) in each node on a map, and - give the design of the track system in plate by correct when the damage (44) in any of the nodes exceeds a value of 1 (18). 5. Procedure for designing a track system (1) according to claim 4, characterized in that in the step of modifying at least one value (24) to choose between the geometry and the parameters that define the fixation (3) , the concrete slab (4), the cement and asphalt mortar cushion (5) and the continuous concrete slab (6), a thickness (25) of the concrete slab (4) is first modified. 6. Procedure for designing a track system (1) according to any of claims 4 or 5, characterized in that in the step of modifying at least one value (24) to choose between the geometry and the parameters that define the fixing (3), the concrete plate (4), the cement and asphalt mortar cushion (5) and the continuous concrete slab (6), at least one value to be chosen between a compression resistance, a modulus elastic and a Poisson coefficient of the parameters that define the concrete plate (4). Method for designing a track system (1) according to any of the preceding claims, characterized in that the dynamic load to be supported by the track system from a target train represented by a complete pulse (14) , is simulated from a pulse corresponding to a known bogie (26) of any train, and comprises the following steps: - perform a temporary scaling of the known bogie pulse (27), by changing a base of times of the known train to a base of times of the target train, obtaining a temporarily scaled pulse, - compose a pulse of a temporarily scaled train corresponding to the target train (28), repeating the temporarily scaled pulse for the bogies of cars and locomotives of the target train, - scaling the amplitude of the pulse of a temporarily scaled train corresponding to the target train (29), multiplying the pulse of a temporarily scaled train corresponding to the target train by a factor, - obtain a complete pulse (38) corresponding to the complete train (30), to adapt the full pulse (38) to the total weight of the complete train, - apply the Fourier transform (33) decomposing the real pulse into harmonics, - find average spectrum of signals (34), - apply anti-Fourier transform (35). 8. Procedure for designing a track system (1) according to any of claims 1 to 6, characterized in that the dynamic load to be supported by the track system from a target train represented by a complete pulse ( 14) is obtained from real data, and includes the following steps: - collect data from real train records (31), represented as real pulses, for each real pulse, - perform a temporary scaling of the actual pulse (32), by changing a base of times of the known train to a base of times of the target train, - perform an amplitude scaling (28), multiplying the temporarily scaled pulse by a factor obtaining a complete pulse (38) corresponding to the target train, - apply the Fourier transform (33) decomposing the real pulse into harmonics, - find average spectrum of signals (34), - apply anti-Fourier transform (35). 9. Procedure for designing a track system (1) according to any of the preceding claims, characterized in that performing the modal analysis (10) comprises calculating the proper modes of vibration and natural frequencies associated with each mode of vibration itself. 10. Procedure for designing a track system (1) according to the preceding claims, characterized in that the step of finding the accumulated damage (44) for each node is made by the law of Palmgren-Miner which sum the damage (44) obtained in the cycles for each voltage level. 11. Plate track system characterized in that it has been designed by the method disclosed in any of the preceding claims.