FR3062911A1 - IMPACT MOBILE, IMPACT TEST DEVICE AND IMPACT TEST METHOD THEREOF - Google Patents

Abstract

The impact mobile (16) includes an impact body (40) for movement to a test surface along a guide frame (14). The impact mobile (16) comprises: - a braking pad (42) movable between a braking position of the body (40) on the frame (14) and a position of release of the body (40) relative to the frame (14), - a releasable locking device (46) of the shoe (42) adapted to move from a holding configuration of the shoe (42) to the release position of the body (40) to an unlocking configuration of the shoe ( 42), the passage of the locking device (46) from its holding configuration to its unlocking configuration being able to be triggered by the deceleration of the impact mobile (16) during an impact of the body (40) against the surface to be tested.

Description

(57) This impact mobile (16) comprises an impact body (40) intended to move towards a surface to be tested along a guide frame (14).

The impact mobile (16) includes:

- a brake shoe (42), movable between a body braking position (40) on the chassis (14) and a body release position (40) relative to the chassis (14),

- A releasable blocking device (46) of the pad (42), adapted to pass from a configuration for holding the pad (42) in the body release position (40) to a configuration for unlocking the pad (42), the passage of the locking device (46) from its holding configuration to its unlocking configuration being suitable for being triggered by the deceleration of the impact mobile (16) during an impact of the body (40) against the surface to be tested.

Impact mobile, impact testing device and associated impact testing method

The present invention relates to an impact mobile comprising an impact body intended to move towards a surface to be tested along a guide frame.

Such an impact mobile is used during mechanical tests to assess and characterize the impact behavior of a part such as an aircraft part, for example an aircraft structural part.

During a test, the mobile falls on the part to cause an impact on the part. This impact typically generates a delamination type damage zone, the properties of which are then measured by non-destructive testing, for example by ultrasound.

As part of these tests, it is necessary to avoid rebounds of the mobile and to cause only one impact on the part. The measurements would indeed be distorted in the event of several successive impacts on the same part.

For this, there are test devices comprising anti-rebound systems of the impact mobile. These devices typically include a sensor which detects the passage of the mobile when it falls towards the part, or during its first rebound, and which actuates a device for blocking the mobile. The locking device is for example a stop on which the mobile comes to rest after impact, or electromagnets immobilizing the mobile after impact.

These solutions are not entirely satisfactory insofar as they are not autonomous, result in reduced mobility of the impact system, depend on the power supply network and require programming of the sensor detecting the passage of the mobile.

The purpose of the invention is therefore to provide an impact mobile which guarantees that a single impact will occur on the part to be tested, while being simple and robust.

To this end, the invention relates to an impact mobile comprising:

- at least one brake shoe, movable relative to the impact body between a braking position of the impact body on the guide frame and a position for releasing the impact body relative to the guide frame,

a releasable blocking device for the brake shoe, capable of passing from a configuration for holding the brake shoe in the release position of the impact body to a configuration for releasing the brake shoe, the passage of the device for blocking its configuration for holding the brake shoe in its configuration for unlocking the brake shoe being capable of being triggered by the deceleration of the impact mobile during an impact of the impact body against the surface to be tested.

According to other advantageous aspects of the invention, the impact mobile comprises one or more of the following characteristics, taken in isolation or in any technically possible combination:

- the passage of the locking device from its configuration for holding the brake shoe to its unlocking position for the brake shoe is triggered exclusively mechanically;

- The impact body is able to fall towards the surface to be tested along a fall axis, the brake shoe being movably mounted on a surface of the impact body inclined relative to the fall axis;

- The mobile comprises an elastic biasing member of the brake shoe towards its braking position of the impact body;

- The locking device comprises a return member, movable relative to the impact body, the return member comprising at least one support tab on the brake shoe, the support tab resting on the shoe braking, when the blocking device is in the holding configuration of the braking shoe, and the support tab being disposed away from the braking shoe, when the blocking device is in the unlocking configuration of the braking shoe;

- The locking device comprises a hook, the hook being movable relative to the return member, between a retaining position of the return member, and an unlocking position of the return member relative to the hook;

- The locking device comprises an elastic biasing member of the hook in its position for retaining the return member;

the blocking device comprises a pusher, the pusher being freely movable in translation in the direction of the axis of fall relative to the impact body, during the deceleration of the impact mobile during an impact of the body d impact against a surface to be tested, the translation of the pusher relative to the impact body causing the locking device to pass into the unlocking configuration;

- The translation of the pusher, moves the hook from its retaining position to its unlocking position of the return member;

- The locking device comprises a damper arranged between the pusher and the hook;

- the pusher and the hook are formed in one piece;

- The brake shoe comprises a braking surface made of a material having a coefficient of friction capable of causing the braking of the mobile;

- The brake shoe includes a braking surface made of an elastomeric material;

- the mobile comprises at least two brake pads, arranged on either side of the impact mobile.

The invention further relates to an impact test device comprising an impact mobile as described above, and a guide frame, the guide chassis comprising at least one guide column, the impact mobile being arranged to move along the guide column during its fall towards the surface to be tested, the or each guide pad of the impact mobile coming into contact with the guide column in its braking position.

The invention finally relates to an impact test method comprising the following steps;

- supply of an impact test device as described above,

- fall of the impact mobile along the or each guide column of the guide frame, the or each brake shoe being in the release position,

- impact of the impact mobile on a surface to be tested and deceleration of the impact mobile,

- passage of the blocking device from its configuration for holding the brake shoe to its unlocking position for the brake shoe, under the effect of the deceleration of the impact mobile, and

- passage of or each brake shoe, from its release position to its position of braking the impact body on the guide frame.

The invention will be better understood on reading the description which follows, given solely by way of example, and made with reference to the appended drawings, in which:

- Figure 1 is a schematic perspective view of an impact testing device according to the invention;

- Figure 2 is a schematic perspective view of an impact mobile of the impact test device of Figure 1, the impact mobile being in an initial position;

- Figures 3 to 5 are schematic perspective views of the impact mobile of Figure 1 at the time of impact of the impact mobile against the surface to be tested.

An impact test device 10 is illustrated in FIG. 1.

This impact test device 10 is intended for carrying out evaluation and characterization tests of the impact behavior of a part to be tested 12. For example, such a test is intended to establish the reduction in mechanical characteristics in residual compression after impact of the part to be tested 12.

The part to be tested 12 is for example a part of an aircraft structural element.

The impact test device 10 comprises a guide frame 14, an impact mobile 16 mounted vertically movable along the guide chassis 14, and a test zone 18.

The impact test device 10 also includes a system 19 for measuring the position of the impact mobile 16 along the guide frame 14.

The guide frame 14 includes a support frame 20 fixed for example to a vertical wall (not shown) arranged next to the test area 18, at least one guide column 22, and a device 24 for releasing the impact mobile 16 .

The guide frame 14 is decoupled from the test area 18. It has no contact with the test area 18. In particular, the guide frame 14 is not supported on the test area 18.

The support frame 20 extends along an axis which is here vertical. It supports the or each guide column 22. In the example of FIG. 1, the guide frame 14 comprises two guide columns 22.

The guide columns 22 define between them an axis of fall, here vertical, and extend between a lower end 26 and an upper end 28.

The lower ends 26 of the guide columns 22 are arranged above and at a distance from the test area 18, so as to provide a space 30 for receiving the part to be tested 12.

The height of each guide column 22 is greater than 1 m, and is a function of the amount of kinetic energy to be supplied to the impact mobile, according to the type of test to be carried out.

Once placed in the reception space 30, the part to be tested 12 has a surface to be tested 32 extending opposite the impact mobile 16, on which the impact mobile 16 is intended to make an impact.

In the reception space 30, the part to be tested 12 is placed on a support tool 33.

The support tool 33 is removable and has a configuration which depends on the test piece 12. More specifically, for a given test piece 12, there is associated a support tool 33 of predetermined shape depending on the shape of the part to be tested

12.

The support tool 33 is thus placed on the test area 18 with the part to be tested

12.

In the example shown in the figures, the tool 33 has an inverted π shape with two supports on which the test piece 12 rests. The impact area of the mobile 16 on the test piece 12 is located between the supports . This tool can be modified according to the desired flexibility conditions.

The release device 24 is suitable for retaining the impact mobile 16 in an initial position, from which the impact mobile 16 drops, and for dropping the impact mobile 16 from the initial position following an order given by an operator.

The release device 24 thus comprises for example a vertical arm 34 visible in FIGS. 1 and 2, movable relative to the impact mobile 16 between a position for retaining the impact mobile 16, and a position for releasing the mobile d impact 16.

The arm 34 defines at its lower end a retaining stop 36 (Figure 2).

When the arm 34 is in its retaining position, the retaining stop 36 is able to cooperate with a recess 38 defined on the impact mobile 16 to retain it in the initial position.

When the arm 34 is in its release position, the retaining stop 36 is arranged at a distance from the recess 38.

The passage of the arm 34 from its retaining position to its release position is caused by an actuating device (not shown) controlled by an operator.

The impact mobile 16 is arranged to move in translation along the or each guide column 22 during its fall towards the surface to be tested 32.

The impact mobile 16 comprises an impact body 40 intended to fall towards the surface to be tested 32 along the guide frame 14, at least one brake shoe 42, an elastic biasing member 44 of the brake shoe 42, and a locking device 46 releasable from the brake shoe 42.

The impact body 40 is able to fall towards the test surface 32 along the axis of fall.

The impact body 40 comprises at least one sliding guide 47A surrounding a guide column 22. The impact body 40 comprises, in the example of FIGS. 2 to 5, two sliding guides 47A per guide column 22 machined in a polymer with a low coefficient of friction to reduce energy losses by friction when the impact mobile 16 is released. Each sliding guide 47A is engaged around a respective column 22.

The impact body 40 has a lower end 47B having a shape suitable for carrying out an evaluation and characterization test of the impact behavior of the part to be tested 12. In the example of FIGS. 2 to 5 , this lower end 47B has a shell shape with a hemispherical end facing downwards.

In the example of the figures, the impact mobile 16 comprises at least two braking pads 42, arranged on either side of the impact mobile 16 to cooperate respectively with each of the columns 22.

Each brake shoe 42 is movable relative to the impact body 40 between a position for releasing the impact body 40 relative to the guide frame 14, illustrated in FIGS. 1 to 3, and a position for braking the body d impact 40 on the guide frame 14, illustrated in FIGS. 4 and 5.

Each brake shoe 42 of the impact mobile 16 is suitable for coming into contact with a guide column 22 in its braking position, in order to maintain the impact mobile 16 in position along the or each guide column 22 .

Conversely, in the release position each brake shoe 42 is disposed completely away from the guide column 22.

Each brake shoe 42 is movably mounted on a surface 48 of the impact body 40 inclined relative to the axis of fall of the impact body 40.

The inclined surface 48 thus comprises an approached region of a guide column 22 and a region remote from the guide column 22. In the example of the figures, the inclined surface 48 is inclined towards the surface to be tested 32, the approached region thus being located above the remote region.

Each brake shoe 42 is in its braking position when it is disposed in the region approached from the inclined surface 48, and is in its release position when it is in the region remote from the inclined surface 48.

Each brake shoe 42 comprises a shoe body 50 and a brake surface 52 secured to the shoe body 50.

The shoe body 50 is for example made of aluminum.

The braking surface 52 is placed opposite a guide column 22, to come into contact with the guide column 22, when the brake shoe 22 is in its braking position.

The braking surface 52 is for example made of a material having a coefficient of friction capable of causing the braking of the mobile.

The coefficient of friction of the material of the braking surface 52, measured according to Standard ISO 15113, is preferably greater than 0.2.

In particular, the braking surface 52 is advantageously made of an elastomeric material, for example rubber.

The elastic biasing member 44 of the brake shoe 42 is configured to resiliently bias the brake shoe 42 permanently towards its braking position of the impact body 40.

The elastic biasing member 44 is supported for example on a surface of the impact body 40.

In the example of the figures, the elastic biasing member 44 is arranged below the brake shoe 22.

The elastic biasing member 44 of the brake shoe 42 is here formed by a spring.

The releasable blocking device 46 of the brake shoe 42 is capable of passing from a configuration for maintaining the or each brake shoe 42 in the release position of the impact body 40 to a configuration for releasing the brake shoe 42.

The passage of the locking device 46 from its configuration for holding the brake shoe 42 to its unlocking position for the brake shoe 42 is capable of being triggered by the deceleration of the impact mobile 16 during an impact of the body. impact 40 against the surface to be tested 32.

The actuation of the passage of the locking device 46 from its configuration for holding the brake shoe 42 to its unlocking position for the brake shoe 42 is exclusively mechanical.

The impact test device 10 is thus devoid of an active system actuating the braking of the impact mobile 16, in particular of an electrical or electromechanical system for actuating the braking of the impact mobile 16.

The locking device 46 comprises a return member 54, a hook 56, an elastic biasing member 58 of the hook 56, and a pusher 60.

The return member 54 is rigid. In the example of the figures, the return member 54 has the shape of a curved rod.

The return member 54 is freely movable relative to the impact body 40. In particular, the return member 54 is here mobile in rotation along an axis of rotation, for example substantially perpendicular to the fall axis.

The return member 54 comprises a central part 62 for guiding in rotation received in a bore of the impact body 40, the bore defining the axis of rotation of the return member 54, a retaining part 64 cooperating with the hook 56, and at least one support tab 66 on a brake shoe 42.

The return member 54 includes a support tab 66 for each brake shoe 42.

The retaining part 64 forms a loop projecting with respect to the guide part 62. It extends perpendicularly to each support tab 66.

The or each support leg 66 is configured to rest on a brake shoe 42, when the locking device 46 is in the holding configuration of the or each brake shoe 42 (FIG. 2), and to be arranged at away from the brake shoe 42, when the locking device 46 is in the unlocking configuration of the brake shoe 42 (FIG. 5). It has a hook-shaped end.

The return member 54 is for example made of steel.

The hook 56 is movable relative to the impact body 40 and relative to the return member 54, between a retaining position of the return member 54, illustrated in FIGS. 2 and 3, and an unlocking position of the return member 54 relative to the hook 56, illustrated in FIG. 4.

In particular, the hook 56 is here movable in translation down along the fall axis.

The hook 56 is inserted into a guide sheath secured to the impact body 40. The guide sheath guides the hook 56 in translation down along the fall axis.

In its retaining position, the hook 56 is capable of grasping and retaining the retaining part 64.

The return member 54 is rigid. It is suitable for holding the or each brake shoe 42 in the release position of the impact body 40, each support tab 66 exerting a force on a brake shoe 42 greater than the force produced by the elastic stress of the elastic biasing member 44 of the brake shoe 42.

In the unlocking position of the return member 54 of the hook 56, the return member 54 is free to rotate in rotation about its axis of rotation. The return member 54 then releases the or each brake shoe 42 while moving away from the brake shoe 42.

The elastic biasing member 58 of the hook 56 is configured to resiliently bias the hook 56 in its position for retaining the return member 54.

In particular, the elastic biasing member 58 of the hook 56 is configured to exert a force on the hook 56 capable of holding it in its position for retaining the return member 54. This force is greater than the sum of the forces produced by each elastic biasing force of each elastic biasing member 44 of each brake shoe 42.

The elastic biasing member 58 of the hook 56 is supported on a surface of the impact body 40.

In the example of the figures, the elastic biasing member 58 of the hook 56 is arranged below the hook 56. The elastic biasing member 58 of the hook 56 is here a spring.

The pusher 60 is arranged in a guide sleeve 68 integral with the impact body 40. The guide sleeve 68 is configured to guide the pusher 60 in translation down along the axis of fall.

The guide sleeve 68 is substantially aligned with the guide sheath of the hook 56.

The pusher 60 is freely movable in translation along the fall axis downward relative to the impact body 40.

In particular, the pusher 60 is movable in translation along the fall axis downward relative to the impact body 40 during the deceleration of the impact mobile 16 following an impact of the impact body 40 against the surface to be tested 32, the translation of the pusher 60 causing the locking device 46 to pass into the unlocking configuration, passing the hook 56 from its retaining position to its unlocking position.

In this example, the pusher 60 exerts a force on the hook 56, during the deceleration of the impact mobile 16 following an impact of the impact body 40 against the surface to be tested 32, capable of passing the hook 56 from its holding position to its unlocking position. This relative displacement of the hook 56 relative to the impact body 40 occurs when the impact body 40 reaches the surface to be tested 32.

Advantageously, the impact body 40 defines a stop 70 capable of stopping the translation of the pusher 60. In the example of the figures, the stop 70 is formed by an upper surface of the guide sheath of the hook 56.

This stop 70 is arranged so that the translational travel of the pusher 60 down along the fall axis causes the hook 56 to pass from its retaining position to its unlocking position.

When the hook 56 is in its position for retaining the return member 54, the hook 56 comprises a part 72 projecting upwards, beyond the stop 70, as illustrated in FIGS. 2 and 3.

The part 72 is able to slide completely in the guide sheath of the hook 56. More precisely, when the pusher 60 is in abutment against the stop 70, the part 72 is arranged below the stop 70 in the guide sheath.

In the embodiment of the figures, the pusher 60 and the hook 56 form two separate parts, the pusher 60 and the hook 56 having here a direct contact, at the level of the part 72 of the hook 56.

The pusher 60 is advantageously disposed above the hook 56.

The mass of the pusher 60 is determined so that the force exerted by the pusher on the hook 56, during the deceleration of the impact mobile 16, is sufficient to overcome friction against the hook 56 and the return member 54, and the elastic stress of the elastic stress member 58 of the hook 56.

The position measurement system 19 is configured to measure the position of the impact mobile 16 along the guide frame 14.

The position measurement system 19 is arranged in a column extending substantially parallel to the guide columns 22.

The position measurement system 19 is for example a magnetostrictive sensor.

The variation of the magnetic field generated during the passage of the mobile 16 in front of the position measurement system 19 makes it possible to determine the exact height of fall relative to the surface to be tested 32.

An impact test method according to the invention will now be described with reference to FIGS. 2 to 5.

The method includes a preliminary step of providing an impact testing device as described above.

The part to be tested 12 is placed in the reception space 30 on the support tool 33.

The impact mobile 16 is placed in its initial position, this initial position being close to the upper end of the guide columns 22.

Each brake shoe 42 is placed in the release position, the blocking device 46 being arranged in its configuration for blocking the brake shoes 42. The support legs 66 of the return member 54 are supported horizontally on the shoes brake 42 and hold each brake shoe 42 in position against the elastic biasing member 44. The hook 56 is held in its position for retaining the return member 54 by the elastic biasing member 58 .

The release device 24 then retains the impact mobile 16 in the initial position.

An operator then triggers the release of the impact mobile 16 by passing the arm 34 from its position for retaining the impact mobile 16 to its release position for the impact mobile 16.

The method includes the fall of the impact mobile 16 along each guide column 22 of the guide frame 14, the brake pads 42 remaining in their release position, and the impact of the lower end 47B of the body d impact 40 on the surface to be tested 32.

As illustrated in FIG. 4, during the impact, the blocking device 46 changes from its configuration for holding the pad of each brake pad 42 to its position for unlocking the brake pads 42.

The pusher 60 being freely movable downward relative to the impact body 40 and having, at the time of impact, substantially the same speed as the impact body 40, the deceleration of the impact body 40 causes the translation of the pusher 60 downwards relative to the impact body 40.

The pusher 60 exerts a force on the hook 56 sufficient to overcome the friction against the hook 56 and the return member 54 and the elastic bias of the elastic biasing member 58. The pusher 60 thus displaces the hook 56 from its position retaining to its unlocking position of the return member 54.

The pusher 60 translates downwards, by pushing the part 72 of the hook into the guide sheath, until the pusher 60 comes into contact with the stop 70, which thus stops the stroke of the pusher 60.

As the return member 54 is no longer retained by the hook 56, the return member 54 pivots in rotation about its axis of rotation. In particular, the support tabs 66 of the return member 54 pivot upwards and release the braking pads 42.

Under the effect of the elastic biasing member 44, each brake shoe 42 moves upwards on the inclined surface 48 and moves transversely from the fall axis to reach its braking position from the impact body. 40. The braking surface 52 of each brake shoe 42 comes into contact with the guide column 22.

The impact mobile 16 rises after its impact on the surface to be tested 32 and is slowed down by its own weight then stops above the surface to be tested 32 after having dissipated all its kinetic energy. It is then held in position along the guide columns 22 by the friction existing between the brake pads 42 and the guide columns 22.

The braking of the impact mobile 16 is mainly due to the effect of gravity and its own weight, the braking does not create vibration.

The test piece 12 is finally removed from the reception space 30, and evaluation and characterization tests of the product impact are carried out by an operator.

As a variant, the pusher 60 and the hook 56 always form two different parts, but with a damper interposed between the pusher 60 and the hook 56. The damper is for example a spring or a part made of an elastic material.

Such a shock absorber makes it possible to dissipate the shock generated during the stopping of the stroke of the pusher 60 against the stop 70. Indeed, such a shock could disturb measurements made by an operator.

In yet another variant, the pusher 60 and the hook 56 are formed in one piece. In this case, the elastic biasing member 58 performs the function of dissipating the kinetic energy accumulated by the pusher 60 progressively before it stops against the stop 70.

The impact mobile 16 provides reliable and quality impact tests.

In particular, the impact mobile 16 allows fully mechanical braking and automatic triggering. The impact mobile 16 is also autonomous and not connected to an electronic braking system.

The design of this impact mobile 16 is simple, has low production costs and is easy to maintain.

Claims (15)

1, - Impact mobile (16) comprising an impact body (40) intended to move towards a surface to be tested (32) along a guide frame (14), characterized in that the mobile d impact (16) includes: - at least one brake shoe (42), movable relative to the impact body (40) between a braking position of the impact body (40) on the guide frame (14) and a position for releasing the body impact (40) relative to the guide frame (14), - a releasable blocking device (46) of the brake shoe (42), suitable for passing from a configuration for holding the brake shoe (42) in the release position of the impact body (40) to an unlocking configuration of the brake shoe (42), the passage of the locking device (46) from its configuration for holding the brake shoe (42) to its configuration for unlocking the brake shoe (42) being capable of being triggered by the deceleration of the impact mobile (16) upon impact of the impact body (40) against the surface to be tested (32). 2, - impact mobile (16) according to claim 1, wherein the passage of the locking device (46) from its configuration for holding the brake shoe (42) in its unlocking position of the brake shoe (42) is triggered exclusively mechanically. 3. - impact mobile (16) according to any one of the preceding claims, in which the impact body (40) is capable of falling towards the surface to be tested (32) along an axis of fall, the brake shoe (42) being movably mounted on a surface (48) of the impact body (40) inclined relative to the axis of fall. 4, - Impact mobile (16) according to any one of the preceding claims, comprising an elastic biasing member (44) of the brake shoe (42) towards its braking position of the impact body (40). 5. - impact mobile (16) according to any one of the preceding claims, wherein the locking device (46) comprises a return member (54), movable relative to the impact body (40), l 'return member (54) comprising at least one support tab (66) on the brake shoe (42), the support tab (66) resting on the brake shoe (42), when the device blocking (46) is in the holding configuration of the brake shoe (42), and the support tab (66) being disposed away from the brake shoe (42), when the locking device (46) is in the brake shoe release configuration (42). 6. - impact mobile (16) according to claim 5, wherein the blocking device (46) comprises a hook (56), the hook (56) being movable relative to the return member (54), between a position for retaining the return member (54) and a position for unlocking the return member (54) relative to the hook (56). 7, - impact mobile (16) according to claim 6, wherein the locking device (46) comprises an elastic biasing member (58) of the hook (56) in its position for retaining the return member ( 54). 8, - impact mobile (16) according to any one of the preceding claims, wherein the locking device (46) comprises a pusher (60), the pusher (60) being freely movable in translation in the direction of l axis of fall relative to the impact body (40), during deceleration of the impact mobile (16) during an impact of the impact body (40) against a surface to be tested (32), the translation of the pusher (60) relative to the impact body (40) causing the locking device (46) to pass into the unlocking configuration. 9, - impact mobile (16) according to claim 8 taken in combination with any one of claims 5 or 6, wherein the translation of the pusher (60) moves the hook (56) from its retaining position to its unlocking position of the return member (54). 10, - Impact mobile (16) according to claim 9, wherein the locking device (46) comprises a damper disposed between the pusher (60) and the hook (56). 11, - Impact mobile (16) according to claim 9, wherein the pusher (60) and the hook (56) are formed in one piece. 12, - Impact mobile (16) according to any one of the preceding claims, in which the brake shoe (42) comprises a braking surface (52) made of a material having a coefficient of friction capable of causing braking. of the mobile (16). 13, - Impact mobile (16) according to any one of the preceding claims, comprising at least two brake pads (42), arranged on either side of the impact mobile (16). 14, - Impact test device (10) comprising an impact mobile (16) according to any one of the preceding claims and a guide frame (14), the guide frame (14) comprising at least one guide column (22), the impact mobile (16) being arranged to move along the guide column (22) as it falls towards the surface to be tested (32), the or each guide shoe ( 42) of the impact mobile (16) coming into contact with the guide column (22) in its braking position. 15, - Impact test method, comprising the following steps: - supply of an impact testing device (10) according to claim 14, - fall of the impact mobile (16) along the or each guide column (22) of the guide frame (14), the or each brake shoe (42) being in the release position, - impact of the impact mobile (16) on a surface to be tested (32) and deceleration of the 5 impact mobile (16), passage of the locking device (46) from its configuration for holding the brake shoe (42) to its unlocking position for the brake shoe (42), under the effect of the deceleration of the impact mobile (16), and - passage of or each brake shoe (42), from its release position to its position 10 for braking the impact body (40) on the guide frame (14). 1/5 2/5