JPS6139310Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention allows strength experiments to be carried out on a flat specimen fixed in a vertical position on a horizontal base by applying a horizontal load while applying a vertical load. The present invention relates to a buckling prevention device used in a test device for applying force to a planar structure.

For example, when conducting a strength test on a shear wall, the weight of the building on the upper floor is always acting on the shear wall of the actual building as a vertical load, and during an earthquake, an alternating load in the horizontal direction is applied to this wall. In order to accurately reproduce the loading conditions during an earthquake and obtain highly reliable experimental results, it is necessary to apply a horizontal load to the specimen while applying a vertical load.

However, if the specimen has a planar shape such as a seismic wall, when a horizontal load is applied while a vertical load is applied, the specimen may twist in the plane due to the horizontal load or collapse due to the vertical load. Buckling is likely to occur, which poses great danger to experimental work.

The present invention provides a buckling prevention device that is highly safe and can avoid such inconveniences, and is versatile enough to be installed in the device even if there is some error in the dimensions of the specimen.

Hereinafter, embodiments of the present invention will be described based on the drawings.

The drawing shows a planar specimen S (a scaled-out model of the actual structure) that can be subjected to a strength experiment by applying a vertical load and a horizontal load to the specimen S. The apparatus is equipped with a vertical load application device A, a horizontal load application device B, a pair of left and right buckling prevention devices C..., a horizontal base D ₁ on which these are installed, and a vertical base D ₂ as a reaction wall. are doing.

The vertical load application device A has a pivot part P ₁ at the lower end and the upper and lower intermediate parts that can swing freely around the axis in the front and rear direction.
A frame body with a substantially gate-shaped side surface formed by a pair of front and rear columns 1a, 1b having P ₂ ... and a connecting member 2 connecting the upper ends of these columns 1a, 1b is mounted on a horizontal base D ₁ . A pair of left and right frames are arranged side by side, and the upper ends of both frames are pivotally connected to each other via a shaft 3 in the front and rear direction.
A hydraulic jack 4 in the vertical direction and a load cell 5 located at the lower end thereof are provided on the lower surface of the connecting member 2, and the lower end of each load cell 5 is pivotally supported via a shaft 6 in the longitudinal direction. Connecting hardware 7...
It is configured by providing.

The horizontal load loading device is provided with a horizontal hydraulic jack 8 on the side of the vertical base D ₂ , and a load cell 9 attached to the tip of the jack 8 is connected to a horizontal guide rail 10 installed on the top of the vertical base D ₂ . A movable hardware 11 that is movable along the axis is fixedly attached, and a longitudinal axis 12 is attached to the tip of the movable hardware 11.
It is constructed by providing a connecting metal fitting 13 which is pivotally supported via. Reference numeral 14 denotes a hanging fitting for the movable hardware 11.

The anti-buckling device C has a frame 15 fixed on a horizontal base D ₁ and a support 17 whose lower end is pivotally pivoted to the frame 15 about a longitudinal axis 16.
The support column 17 is provided with a plurality of connecting metal fittings 19 that are swingable around a support shaft 18 in the longitudinal direction, and a turnbuckle mechanism 20 that adjusts the vertical distance between the support shafts 18. There is. The frame body 15 is provided with mutually parallel vertical plates 21 located on both the front and rear sides of the support column 17, and both ends of each of the support shafts 18 are freely inserted through these vertical plates 21. Through-holes 22 long in the left-right direction are provided. At both ends of the support shaft 18,
A pair of washers 2 each having a flat bearing 23 welded to the surface facing the plate surface surrounding the through hole 20.
4..., and these washers 24... are used to sandwich the vertical plate 21... from both sides.
8 can be moved smoothly in the left-right direction within the range of the through-holes 20, but movement in the front-back direction (i.e., the axial direction of the support shaft 18) is limited to the washer 24... and the vertical plate 21.
It is configured to be blocked by... 25
... is a nut that is screwed onto the support shaft 18.

Various flat specimens S can be used, but in this example, as shown in FIG.
A pair of left and right columns 26a, 26b, a beam 27, and a shear wall 2
8 and a steel-framed reinforced concrete specimen S having a base 29 for stably installing these in a vertical position on a horizontal base D ₁ . The pressure receiving plates 30..., 31 are fixedly installed, respectively, and the pillars 26
Beam-like protrusions 33 having connecting plates 32 at their tips are provided at appropriate intervals in the vertical direction on both end surfaces of the beams a and 26b in the left-right direction.

In addition, a large number of through holes 34 are drilled in the horizontal base D ₁ and the horizontal base D ₂ at appropriate intervals in the front, back, left, and right directions, and are inserted through a screw shaft 35 made of high-tensile steel and a nut-shaped body 36. It is configured to fix each of the above-mentioned devices A, B, C and the specimen S.

According to the above configuration, the specimen S is placed on a horizontal base.
D ₁ is fixed in a vertical position, and the pressure receiving plates 30 on the top of the pillars 26a and 26b are connected to the connecting hardware 7 of the vertical load loading device A, and the pressure receiving plate 31 at one end of the beam 27 is connected to the horizontal load loading device B. The connecting plates 32 at the tips of the protrusions 33 are connected to the connecting hardware 19 of the buckling prevention device C by connecting them to the hardware 13 with bolts, nuts, etc., respectively.
In this state, the hydraulic jacks 4 are extended to apply a constant vertical load, and the hydraulic jacks 8 are extended and contracted to apply a horizontal load to conduct experiments such as shear strength. This allows experiments to be conducted under load conditions that approximate the loads that actually act during an earthquake, and highly reliable experimental results can be obtained.

In addition, the specimen S deforms in the left-right direction when subjected to a horizontal load, and the connecting metal fitting in which the connecting plate 32 at the tip of the beam-like protrusion 33 protruding from both left and right end surfaces is pivoted to the support 17. 19..., and each support 17... is configured to be swingable in the left-right direction with the shaft 16 at the lower end as a pivot point, and each connecting metal fitting 1
9 are configured to be able to swing vertically around the support shaft 18 relative to the support columns 17, so that deformation of the specimen S in the left and right direction due to horizontal loads is not hindered.
However, the movement of the support shaft 18 in the axial direction, that is, the connecting metal fittings 19... and the columns 17 supporting them...
The vertical plate 21 of the frame 15...
This prevents the specimen S from twisting in plan (tilting in plan view) due to horizontal loads, collapsing the specimen S in the front-back direction due to vertical loads, and preventing the specimen S from collapsing in the front-rear direction or sitting. This can prevent bending.

The vertical load application device A is made rigid so that it can stand on its own by connecting the columns 1a, 1b, etc. with appropriate members when the specimen S is not set, and when attaching and detaching the members, The upper part of the apparatus A is suspended and supported by a hoist (not shown) or the like.

As described above, in the present invention, a pair of left and right frames located on the left and right sides of the specimen are fixedly mounted on a horizontal base, and these frames have a pair of frames facing the left and right end surfaces of the specimen. A column is provided swingably around a longitudinal axis provided at its lower end, and a plurality of connecting metal fittings for connecting the specimen are pivoted to the column so as to be pivotable about a longitudinal axis. A turnbuckle mechanism is provided to adjust the vertical spacing between these support shafts, and the frame body is provided with vertical plates parallel to each other located on both sides of the front and back of each support shaft, and these vertical plates include A through hole is provided through which the part is freely inserted, and a washer is provided at both ends of the support shaft, and a flat bearing is attached to the surface facing the plate surface surrounding the through hole. Since a pair of buckling prevention devices on the left and right sides were installed to prevent the connecting hardware from moving in the front-rear direction using plates, when a horizontal load was applied to the specimen while a vertical load was applied, the specimen was prevented from moving due to the horizontal load. Deformation in the left and right direction is not hindered by the buckling prevention device, and movement of the connecting hardware in the front and back direction is prevented by the vertical plate of the frame and the washer in contact therewith. Even though the specimen is flat and receives vertical and horizontal loads,
It is possible to reliably prevent the specimen from twisting in a plane (tilting in plan view) due to horizontal loads, collapsing in the front-back direction, buckling, etc. due to vertical loads, and ensuring the safety of experimental work.

In addition, the turnbuckle mechanism provided on the column allows adjustment of the vertical spacing of each connecting metal fitting, so even if there is a slight error in the dimensions of the specimen, it can be set in the anti-buckling device, providing versatility. be.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Figure 1 is a front view, Figure 2 is a side view, Figure 3 is a perspective view of main parts, and Figure 4 is a front view.
The figure is a schematic front view showing the specimen and its attached state. C...Buckling prevention device, D ₁ ...Horizontal base, S
...Specimen, 15...Frame, 16...Shaft, 17...
...Strut, 18... Support shaft, 19... Connecting hardware, 20
... Turnbuckle mechanism, 21 ... Vertical plate, 22
...Through hole, 23...Flat bearing, 24
...Washer.

Claims (1)

[Scope of utility model registration request] In a load application experiment device for carrying out a strength experiment on a planar specimen S fixed in a vertical position on a horizontal base _D1 by applying a vertical load and a horizontal load to the specimen S, a pair of left and right frame bodies ₁₅ are fixedly installed on the horizontal base D1 on both the left and right sides of the specimen S, and each frame body 15 is provided with a support 17 facing the left and right end faces of the specimen S, which is swingable about a front-rear axis 16 provided at the lower end thereof, and a plurality of connecting metal fittings 19 for connecting the specimens S are pivotally attached to each support shaft 18 in the front-rear direction on each support 17, and a turnbuckle mechanism 20 is provided for adjusting the vertical distance between the support shafts 18. The frame body 15 is provided with parallel vertical plates 21 located on both the front and rear sides of each support 17, and the vertical plates 2 are arranged so that the vertical distance between the vertical plates 2 is adjusted.
1 is provided with through holes 22 through which both ends of each support shaft 18 are freely inserted, and washers 24 with flat bearings 23 attached to the surfaces facing the plate surfaces surrounding the through holes 22 are provided at both ends of the support shaft 18, and a buckling prevention device C is provided in which these washers 24 and vertical plates 21 prevent the support shaft 18 from moving in the axial direction.