JP7019498B2 - Eaves impact test method - Google Patents

Description

The present invention relates to an impact test method for eaves. More specifically, the present invention relates to an impact test method for measuring the impact resistance of eaves of a house or the like when a falling object such as falling snow collides.

Conventionally, as an impact test on a building, a test has been conducted on the assembled building itself or a test object (outer wall, roof, eaves, flooring, etc.) attached in a state suitable for use. Steel balls and sandbags are often used as impact-imparting bodies that collide with the test object to give an impact. The impact resistance is evaluated based on whether or not a deterioration in function or a change in appearance (deformation, damage, etc.) occurs in the test object due to the collision (Non-Patent Document 1).

A conventional impact test method for eaves of a house or the like will be described with reference to FIG. FIG. 3 is a schematic view of a test sample 10 in which the eaves 12 to be tested are attached to the wall 11 in a state similar to normal use. In the test sample 10, the eaves 12 are provided on the wall 11 in a one-sided manner so as to protrude from the wall 11.

As shown in FIG. 3, the rope 14 is connected to the weight 13 and the rope 14 is lifted so that the weight 13 is positioned at a predetermined height h1 above the eaves 12 (suspended state). After that, by releasing the lifted rope 14, the suspended state of the weight 13 is released and the weight 13 is dropped as shown by the arrow in the figure. Then, the weight 13 is made to collide with the eaves 12 installed at the position directly below the eaves 12, and the state of the eaves 12 after the collision is verified.

As the weight 13, a leather bag filled with sand is often used. In FIG. 3, since the weight 13 is suspended, it is in a state of spreading downward in a fan shape due to gravity. The upper portion of the fan-shaped weight 13 is a void S not filled with sand.

Japan Building Research Institute, "Easy-to-understand test series Pressure-06 torsional strength, vertical load strength, impact resistance test", [online], [Search on March 26, 2018], Internet < URL: http://www.gbrc.or.jp/assets/test_series/documents/cl_06.pdf>, Japan Building Research Institute Testing and Research Center Environment Department Wind Resistance Test Room

In such an impact test by free fall of the weight 13, sand moves in the bag at the time of falling due to the presence of the void S, and the shape of the weight 13 at the time of collision and its change are varied. As a result, the impact (impact force) on the eaves 12 tends to vary. Therefore, it was necessary to perform a large number of tests in order to determine the impact resistance of the eaves 12.

Since the impact test on a building such as an eave is performed on the building itself or a test object attached in a state similar to the use, there is a problem that it takes cost and labor if the number of trials of the impact test is large.

The present invention has been made in view of the above circumstances, and provides an impact test method capable of reducing the number of trials of an impact test for eaves of a house or the like.

In order to solve the above-mentioned problems, the impact test method of the eaves of the first invention is
An impact test method for eaves to evaluate the impact resistance of the eaves by dropping the impact-imparting body from the eaves at a predetermined height and causing the impact-imparting body to collide with the eaves.
The impact-imparting body is a bag filled with sand adjusted to a density of 1,500 kg / m ³ , and the opening of the bag is closed so that no gap is formed between the inner surface of the bag and the sand. Has been
The bag is polyethylene
One end of the rope is attached to the impact-imparting body,
A fixed pulley for suspending the impact-imparting body in a fallable state,
A holding portion capable of holding the impact-imparting body at a predetermined height position and releasing the holding thereof,
Is provided,
A suspension step of suspending the impact-imparting body at a predetermined height by hanging the rope on the fixed pulley and holding the other end of the rope in the holding portion.
A drop step of dropping the impact-imparting body toward the eaves by releasing the holding of the other end of the rope by the holding portion and releasing the suspension state of the impact-imparting body.
It is characterized by having.

According to the first invention, the impact-imparting body is a polyethylene bag filled with sand having a density of 1,500 kg / m ³ . Then, after the impact-imparting body is filled with sand, its opening is closed so that no void is formed in the bag. Since the polyethylene bag has excellent flexibility, the shape of the bag can be made to follow the shape of the filled sand, and it is easy to seal it so that no voids are formed. Since such an impact-imparting body has almost no voids filled with sand in the bag, it is difficult for sand to move in the bag even if it is dropped from a suspended state, and an impact is applied when the bag is dropped or collided. The shape of the body is less likely to change, and the variation in shape changes is lessened. As a result, variations in impact (impact force) can be suppressed.

Therefore, according to the first invention, it is possible to reduce the variation in impact, thereby reducing the number of impact test trials.

The impact test method of the second invention is described in the first invention.
The weight of the impact-imparting body is 3 kg or more and less than 6 kg, and the predetermined height is 4 m or more and 6 m or less, or the weight of the impact-imparting body is 6 kg or more and the predetermined height is It is characterized by being 2 m or more and 6 m or less.

If the weight of the impact-imparting body and the drop height at which the impact-imparting body is dropped satisfy the above conditions, the impact test can be further suppressed in variation.

The impact test method of the third invention is described in the first or second invention.
The impact-imparting body is provided with a string that hangs downward.
The suspension step is characterized in that the impact-imparting body is lifted to a predetermined height using the length of the string as an index.

When performing an impact test, it is first necessary to arrange the impact-imparting body at a predetermined height. When the impact-imparting body is suspended, the string hangs toward the drop point. As a result, it becomes an index of a predetermined height when the impact-imparting body is suspended, and is excellent in convenience.

The impact test method of the fourth invention is characterized in that, in any one of the first to third inventions, the sand is densified by adding water.

By adjusting the amount of sand filled in the bag by adding water, the sand in the bag becomes moist. Such moist sand is less likely to move within the bag than dry sand. As a result, the change in the shape of the impact-imparting body at the time of dropping or collision can be further suppressed, and the variation in the shape change can be further suppressed.

A conceptual diagram showing an example of an impact test method. The figure which shows the equipment of the verification experiment. A conceptual diagram showing an impact test of a conventional eaves such as a house.

When a falling object collides with the eaves of a house or the like due to falling snow or the like, the eaves may be deformed or destroyed by the impact applied. The present embodiment is an impact test method for evaluating the impact resistance of the eaves for the purpose of ensuring the strength of the eaves so that the eaves are not destroyed by the collision of such a falling object.

Hereinafter, the impact test method of the present invention will be described based on the embodiment shown in FIG. In the embodiment, the case where the test object for evaluating the impact resistance is the eaves of a house will be described as an example.

FIG. 1 is a schematic view of the eaves to be tested mounted on the wall in a state similar to normal use. As a test sample 10, the eaves 12 are provided on the wall 11 in a one-sided manner so as to protrude from the wall 11. Hereinafter, the protruding direction of the eaves 12 means a direction perpendicular to the wall 11, and the width direction of the eaves 12 means a direction parallel to the wall 11.

A hoist crane 31 (only a part of which is shown) is arranged above the eaves 12. The hoist crane 31 is provided with a hook 32 so that the hook 32 is located above the drop point to the eaves 12 subject to the impact test (for example, above the center of the eaves in the protruding direction and the width direction). Is located in. A pulley 23 is hung on the hook 32. The hoist crane 31 and the hook 32 hold the pulley 23 so that it does not move during the impact test. Therefore, the hoist crane 31, the hook 32, and the pulley 23 constitute a "constant pulley".

A rope 24 is hung on the pulley 23, and a weight 21 is suspended from one end 24a of the rope 24. That is, one end 24a of the rope 24 is attached to the weight 21 (for example, the binding band 22 described later), and the rope 24 is hung on the pulley 23, so that the weight 21 is lifted by the rope 24 and is above the eaves 12. It is held in (suspended state). The pulley 23 supports the weight 21 to be suspended at a predetermined height h2.

A stand 35 (only a part of which is shown) is installed on the front side of the eaves 12 which is the test sample 10, and a clamp 36 is provided on the stand 35. The other end 24b of the rope 24 is fastened to the clamp 36. In the present embodiment, the other end 24b of the rope 24 is formed into a ring shape, and the other end 24b of the rope 24 is held by the clamp 36 by hanging the ring portion on the clamp 36. As a result, the weight 21 is suspended by the pulley 23 and held by the stand 35 and the clamp 36 so as to have a predetermined height h2.

In the impact test method of the present embodiment, when the other end 24b of the rope 24 fastened to the clamp 36 is released from the clamp 36 (holding is released), the weight 21 falls due to gravity. As a method of releasing the other end 24b of the rope 24 by the clamp 36, the operator may remove the ring portion from the clamp 36, or the operator may cut off the other end 24b (ring portion or the like) of the rope 24. It may be released from the clamp 36.

That is, the stand 35 and the clamp 36 can hold the weight 21 at a predetermined height h2 and release the held state (in other words, the suspended state of the weight 21). The stand 35 and the clamp 36 correspond to the "holding portion".

One end 25a of the string 25 is attached to the lowermost part of the weight 21. One end 25a of the string 25 is attached by being sewn to the weight 21 or attached by tape or the like. The length of the string 25 is the same as the predetermined height h2. The other end 25b of the string 25 is fixed to the target drop point of the eaves 12 with tape or the like (not shown). As a result, the string 25 serves as an index for lifting the weight 21 to a predetermined height h2.

In the present embodiment, the weight 21 is a bag filled with sand adjusted to a density of 1,500 kg / m ³ , and the opening of the bag is closed with a binding band 22 so as not to create a gap in the bag. ing. The weight 21 corresponds to the “impacting body”.

In the present embodiment, a polyethylene bag is used as the bag for filling sand. If the bag is made of polyethylene, the bag can be deformed along the shape of the filled sand, so that the bag can be closed by the binding band 22 so as not to create a gap in the bag (between the inner surface of the bag and the sand).

The shape of the polyethylene bag is not particularly limited, such as a flat bag, a self-standing bag, a gusset bag, etc., but a flat bag-shaped sandbag is particularly preferable. The size of the sandbag is preferably 480 mm wide x 620 mm long.

As the sand to be filled in the bag, sand conforming to JIS A1518 (1996) is used. That is, the sand that has passed through the 2 mm sieve and stays on the 0.6 mm sieve is adjusted to a density of 1500 kg / m ³ . For example, water may be added to the sand to adjust the density to 1,500 kg / m ³ . By adding water to the sand to adjust the density, the sand in the bag becomes moist. Compared to dry sand, wet sand suppresses the movement of sand in the bag, which further suppresses the change in the shape of the weight 21 when dropped or collided, and further suppresses the variation in the shape change. Ru. Therefore, the sand filled in the weight 21 is hydrated and adjusted, so that the variation in impact is reduced. Further, when the sand is in a damp state, the weight 21 is similar to the state of snow, and is therefore preferable as the weight 21 for the impact test on the eaves due to falling snow.

Here, in the impact test method of the present embodiment, the weight of the weight 21 is preferably 2 kg or more, more preferably 4 kg or more, still more preferably 6 kg or more. The upper limit of the weight of the weight 21 is not particularly limited, but is preferably 20 kg or less, more preferably 18 kg or less, and further preferably 15 kg or less from a practical point of view when performing an impact test. ..

In the impact test method of the present embodiment, the height h2 at which the weight 21 is dropped is not particularly limited, but a lower one is preferable from the practical point of view when performing an impact test. Therefore, the drop height h2 is preferably 30 cm to 10 m, more preferably 50 cm to 8 m, still more preferably 1 m to 6 m, and particularly preferably 2 to 6 m.

Since the variation in impact is affected by the weight and height, it is preferable to consider the balance. For example, when the weight of the weight 21 is 3 kg or more and less than 6 kg, if the predetermined height (drop height) h2 is 4 m or more (preferably 4 m or more and 6 m or less), the variation in impact is reduced. When the weight 21 is 6 kg or more and the predetermined height h2 is 2 m or more (preferably 2 m or more and 6 m or less), the variation in impact is sufficiently reduced.

The shape of the weight 21 (the shape after being closed by the binding band 22) is spherical so that the collision with the eaves 12 at the time of the initial collision is close to the point from the viewpoint of shape stability. However, other shapes may be used.

The size of the portion of the weight 21 filled with sand (excluding the corner portion of the sandbag) is preferably substantially spherical with a diameter of 30 cm or less, and is substantially spherical with a diameter of 25 cm or less in the suspended state. Is more preferable. Further, it is preferably substantially spherical with a diameter of 12 cm or more, and more preferably substantially spherical with a diameter of 15 cm or more.

Since the sandbag is closed so as not to generate voids, the voids are minimized even at the corners of the sandbags. In the present embodiment, since the sand is hydrated, the movement of the sand in the bag is suppressed as compared with the dry sand. Therefore, even if there are a few voids in the corners, the influence of the voids (movement of sand to the voids) can be suppressed.

In the impact test method of the present embodiment, the rope 24 is for suspending the weight 21, and is not particularly limited as long as it has sufficient strength to hold the weight 21, and is not particularly limited as long as it has sufficient strength to hold the weight 21, such as cotton, linen, nylon, polyester, and polyethylene. , Polypropylene, vinylon and the like can be used. The length and width of the rope 24 may also be appropriately selected depending on conditions such as the weight of the weight 21 and the height h2.

The string 25 is preferably a string that is thinner or thinner than the rope 24 so as not to interfere with the fall and collision. As the string 25, one made of cotton, linen, silk, nylon, polypropylene or the like can be appropriately used.

Further, the size of the pulley 23 and the like are not particularly limited, and may be appropriately selected according to the weight of the weight 21 and the shape of the rope 24. The hoist crane 31 and the hook 32 for holding the pulley 23, the stand 35 and the clamp 36 for holding the rope 24, and the like may be substituted by other means for obtaining the same effect.

Next, the test procedure will be described.

Confirm that there is no distortion or the like in the part of the eaves 12 where the impact is applied (target drop point). After that, the rope 24 attached to the weight 21 is hung on the pulley 23, and the other end 24b of the rope 24 is held by the clamp 36 of the stand 35. As a result, the weight 21 is suspended.

Next, the hoist crane 31 is moved so that the weight 21 in the suspended state is located at the target drop point and the string 25 is not slackened. As a result, the weight 21 is in a state of being directly above the target drop point and suspended at a predetermined height position h2. The process corresponds to the "suspension process".

Then, after confirming that the shaking of the weight 21 has stopped, the suspended state of the weight 21 is released by releasing the other end 24b of the rope 24 from the clamp 36. When the suspended state is released, the weight 21 freely falls toward the eaves 12 (arrow in FIG. 1), and the weight 21 collides with the vicinity of the target drop point of the eaves 12. The process corresponds to the "falling process".

After the collision of the weight 21, the eaves 12 are visually inspected for deformation or damage such as dents, cracks, peeling, and bending. For the test results, record the presence or absence of deformation and damage. When recording the test results, the test conditions (drop height h2, weight of weight 21, size of eaves 12 to be tested, number of impacts (drops), etc.) are added.

It can be confirmed that the impact test method of the present embodiment has high reproducibility (less variation) by, for example, a verification method described later. If the conditions are more preferable, it can be confirmed that the error of the impact force is less than 10% by the verification method described later. That is, the impact test method of the present embodiment suppresses the change in the shape of the weight 21 when the weight 21 is dropped and collided with the test object (eaves) in a free-fall state or a state close to free-fall, and has a shape. Suppress the variation of changes in. As a result, the variation in impact can be reduced, and the number of trials of the impact test can be reduced.

Hereinafter, according to the impact test method of the present embodiment, an experiment was carried out to verify that the test has little variation in impact force.

Verification experiment 1
FIG. 2 shows a device for performing a verification experiment.

As shown in FIG. 2, the steel plate 42 was installed, and three load cells 41a, 41b, 41c were installed on the surface of the steel plate 42 so that the load cells 41a, 41b, 41c were the vertices of an equilateral triangle. Then, the steel plate 43 was placed on the load cells 41a, 41b, 41c, and the load cells 41a, 41b, 41c were sandwiched by the steel plates 42, 43.

The load cells 41a, 41b, 41c are connected to the data logger 45 by the wirings 44a, 44b, 44c, respectively.

As shown in FIG. 2 (similar to FIG. 1), the weight 21 is suspended by using a hoist crane 31, a pulley 23, a stand 35, a clamp 36, and the like. In this experiment, the weight 26 is attached to the other end 25b of the string 25, and the weight 26 is arranged so as to be located at the drop target point 46. Also in the above embodiment, the weight 26 may be attached instead of fixing the other end 25b of the string 25 to the eaves 12 as in this experiment. The fall target point 46 is located near the center of gravity of an equilateral triangle formed by the load cells 41a, 41b, and 41c.

The weight 21 was prepared as follows.

Water was added to sand having a density of 1464 kg / m ³ to adjust the density of the sand to 1500 kg / m ³ . The adjusted sand was filled in a polyethylene sandbag (width 48 cm × length 62 cm, product name: sandbag), and the mouth of the bag was closed with a binding band 22 so that no voids remained. In the suspended state, the weight 21 had a substantially spherical shape in which the sand-filled portions had the following sizes, except for the corner portions of the sandbags. Since the sandbag is closed so as not to generate voids, the voids are minimized even at the corners of the sandbags.

・ 3 kg weight 21 ... almost spherical shape with a diameter of 16 cm ・ 4 kg weight 21 ... almost spherical shape with a diameter of 17 cm ・ 5 kg weight 21 ... almost spherical shape with a diameter of 19 cm ・ 6 kg weight 21 ... almost spherical shape with a diameter of 20 cm.

The tools used in the verification experiment are shown below.

Pulley 23: Diameter 60 mm, width of rotating part (steel) 20 mm
Load cells 41a, 41b, 41c: Two types of load cells are used in combination; one load converter 200 kgf (model number: 9E01-L21-200K, diameter 100 mm, height 80 mm) and a load converter 5tf (model number: 9E01-L22). Data logger 45: Universal Data Acquisition System data logger (model number: UDAS) using two -5T, diameter 100 mm, height 80 mm)
Rope 24: Cotton string steel plate 42, 43 with a thickness of 5 mm: Size 90 cm x 90 cm (thickness 9 mm).

In the verification experiment 1, the operator removed the other end 24b (ring portion) of the rope 24 fastened to the clamp 36, and the operator released the other end 24b of the rope 24 to drop the weight 21. Then, the weight of the weight 21 and the height h2 were changed, and the impact force (N) generated by the drop of the weight 21 was measured using the load cells 41a, 41b, 41c. The impact force (N) due to the drop of the weight 21 is the sum of the impact forces (N) measured by the load cells 41a, 41b, 41c. As the impact force measured by each load cell 41a, 41b, 41c, the maximum value of the impact force was adopted.

The same conditions were measured 10 times, and for the impact force obtained by the 10 experiments, the average value of the impact force and the error (%) of the impact force were calculated as the degree of variation in the impact force (± 3σ). (See Table 1).

From the results in Table 1, the condition that the error of the impact force is less than 10% was obtained. It is considered that the weight of the weight 21 and the height h2 to be dropped satisfy the following conditions.

(1) The weight 21 is 3 kg or more and less than 6 kg, and the drop height h2 is 4 m or more. (2) The weight 21 is 6 kg or more and the drop height h2 is 2 m or more.

Therefore, it is suggested that if the above (1) or (2) is selected, the reproducibility is higher than that of the other conditions of the verification experiment 1, and the number of trials can be further reduced.

The variation in impact is theoretically reduced as the drop height increases and the weight increases. Therefore, when the error was less than 10%, the impact test (verification experiment) under the weight of the weight 21 was completed. Therefore, if the drop height h2 is 6 m, the weight of the weight 21 is considered to have an error of less than 10% when the weight is 3 kg or more and less than 6 kg, and an error of less than 6.5% when the weight 21 is 6 kg.

Comparative experiment In order to compare with the result of the verification experiment 1, comparative experiments 1 to 5 were performed.

Comparative experiment 1
In Comparative Experiment 1, the rope 24 attached to the weight 21 was held by hand without using the pulley 23, and the weight 21 was dropped by releasing the rope 24 from the hand. That is, except that the rope 24 is held by hand at the position where the height of the weight 21 is h2, and then the rope 24 is released from the hand at the position of the height h2 to drop the weight 21. An experiment was conducted in the same manner, and the average value of the impact force and the error of the impact force were calculated (Table 2).

Comparative experiment 2
In Comparative Experiment 2, the rope 24 attached to the weight 21 was held by the clamp 36 without using the pulley 23, and the weight 21 was dropped by releasing the rope 24 from the clamp 36. That is, except that the rope 24 is held by the clamp 36 of the stand 35 at the position where the height of the weight 21 is h2, and then the rope 24 is released from the clamp 36 at the position of the height h2 to drop the weight 21. An experiment was conducted in the same manner as in the verification experiment 1, and the average value of the impact force and the error of the impact force were calculated (Table 2).

From the results of Comparative Experiments 1 and 2, it was confirmed that the error of the impact force was large when the pulley 23 was not used. It can be seen that when the impact test is carried out by this method, the number of trials is large because the reproducibility is low.

Comparative experiment 3
In Comparative Experiment 3, the same experiment as in Comparative Experiment 1 was performed using the following weights.

After filling the polyethylene sandbag with sand adjusted to a predetermined weight density of 1,500 kg / m ³ , the sandbag was closed with a string attached to the upper part of the sandbag to make a weight. Therefore, the weight includes a space (void) that is not filled with sand.

In the comparative experiment 3, the experiment was carried out in the same manner as in the comparative experiment 1 except that the weights of 3 kg and 6 kg closed by the string on the upper part of the bag were used instead of the weight 21. In Comparative Experiment 3, in the case of a weight of 3 kg, the error of impact force is 37.3% (average impact force of 897N) when dropped from 1 m, and in the case of weight 21 of 6 kg, the error of impact force when dropped from 1 m. It was 60.4% (average impact force 1871N).

Comparative experiment 4
In Comparative Experiment 4, the same experiment as in Comparative Experiment 2 was performed using the weight of Comparative Experiment 3.

In Comparative Experiment 4, in the case of a weight of 3 kg, the error of impact force is 95.6% (average impact force of 620 N) when dropped from 1 m, and in the case of a weight of 6 kg, the error of impact force is 47 when dropped from 1 m. It was .1% (average impact force 1199N).

From the results of Comparative Experiments 3 and 4, it was confirmed that the error of the impact force was larger than that of Comparative Experiments 1 and 2 in the case of the weight not closed by the binding band 22. Therefore, it was suggested that it is important that the weight 21 in the impact experiment is closed so that no void is formed.

Comparative experiment 5
In the comparative experiment 5, the experiment was carried out in the same manner as in the verification experiment 1 except that the bag of the weight 21 was changed from the polyethylene sandbag to the polypropylene sandbag (width 48 cm × length 62 cm). However, since it is made of polypropylene, the entire bag is inflexible, and even if the mouth of the bag is closed so that the bag does not have a gap, the gap remains and the sand in the bag can move.

An impact test was conducted by dropping a weight of a polypropylene sandbag filled with 6 kg of sand having a density of 1500 kg / m ³ from a position of 2 m in height. As a result, the error of the impact force was 10.8% (the average impact force was 3141N).

In Comparative Experiment 5, it was confirmed that the variation in impact was reduced by making the bag of the weight 21 made of polyethylene when dropped under the same conditions. The reason why polyethylene is preferable to polypropylene is that polyethylene bags are more flexible than polypropylene bags. That is, when the binding band 22 closes the bag so as not to generate voids, the polyethylene bag can be deformed along the shape of the filled sand as compared with the polypropylene bag. As a result, the polyethylene bag can be closed by the binding band 22 in a state where the voids can be reduced as compared with the polypropylene bag.

As described above, from the results of the verification experiment 1 and the comparative experiments 1 to 5, in the system of the verification experiment 1, there are many conditions (weight of the weight 21 and drop height h2) in which the error can be made less than, for example, 20%. You can see that. As a result, it can be said that the impact test method of the present embodiment reduces the variation in impact and improves the reproducibility. That is, when the weight 21 is filled with sand in a polyethylene bag, the bag is closed so that no voids are formed, and the pulley 23 is used when the suspended state of the weight 21 is released, the impact is increased. Variation is reduced and reproducibility is improved.

Further, if the error of the impact force is less than 10%, it can be said that the impact test method has higher reproducibility and can further reduce the number of trials. The condition that the error of the impact force is less than 10% is that the weight 21 is filled with sand in a polyethylene bag, the bag is closed so that no voids are formed, and the suspended state of the weight 21 is released. It is considered that the pulley 23 is used, and the weight of the weight 21 and the height h2 to be dropped satisfy the above condition (1) or (2). Further, under the condition of (2), the error of the impact force can be less than 6.5%, so that the number of trials of the impact test can be further reduced.

12 ... Eaves, 21 ... Weight, 22 ... Cable ties, 23 ... Pulleys, 24 ... Rope, 24a ... One end of rope 24, 25 ... Rope, 35 ... Stand, 36 ... Clamp, h2 ... Predetermined height.

Claims (4)

An impact test method for eaves to evaluate the impact resistance of the eaves by dropping the impact-imparting body from the eaves at a predetermined height and causing the impact-imparting body to collide with the eaves.
The impact-imparting body is a bag filled with sand adjusted to a density of 1,500 kg / m ³ , and the opening of the bag is closed so that no gap is formed between the inner surface of the bag and the sand. Has been
The bag is polyethylene
One end of the rope is attached to the impact-imparting body,
A fixed pulley for suspending the impact-imparting body in a fallable state,
A holding portion capable of holding the impact-imparting body at a predetermined height position and releasing the holding thereof,
Is provided,
A suspension step of suspending the impact-imparting body at a predetermined height by hanging the rope on the fixed pulley and holding the other end of the rope in the holding portion.
A drop step of dropping the impact-imparting body toward the eaves by releasing the holding of the other end of the rope by the holding portion and releasing the suspension state of the impact-imparting body.
The impact test method of the eaves. The weight of the impact-imparting body is 3 kg or more and less than 6 kg, and the predetermined height is 4 m or more and 6 m or less, or the weight of the impact-imparting body is 6 kg or more and the predetermined height is The impact test method for eaves according to claim 1, wherein the height is 2 m or more and 6 m or less. The impact-imparting body is provided with a string that hangs downward.
The impact test method for eaves according to claim 1 or 2, wherein in the suspension step, the impact-imparting body is lifted to the predetermined height using the length of the string as an index. The impact test method for eaves according to any one of claims 1 to 3, wherein the sand is densified by adding water.

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