CN106289961A - A kind of device based on sound wave sensing determination material impacts recovery coefficient - Google Patents

Abstract

A kind of device based on sound wave sensing determination material impacts recovery coefficient disclosed by the invention, device includes base, support, crossbeam, collision ball, impingement plate, sound transducer, capture card and computer；Described impingement plate and support are fixed on base, crossbeam is rack-mount, and crossbeam is positioned at above impingement plate, and collision ball is embedded on crossbeam, sound transducer is arranged on impingement plate side and the position fallen near collision ball, and described sound transducer, capture card are sequentially connected with computer；Described collision ball is respectively adopted different collision materials and makes from impingement plate.Present configuration can accurately measure its collision recovery coefficient by the audio frequency information in time that collision produces, and measures much easier, and certainty of measurement is the highest.

Description

A kind of device based on sound wave sensing determination material impacts recovery coefficient

Technical field

The present invention relates to testing of materials technical field, particularly to one based on sound wave sensing determination material impacts restorer The device of number.

Background technology

Collision is the physical phenomenon generally existed.Wherein recovering collision coefficient is the important ginseng characterizing collision energy loss Number.In the exploitation design of multiple industries equipment such as broken, screening, automobile, it is required to measure and recovers collision coefficient.And this parameter Relevant to the material type of mutual collision object.Different materials collides, and its collision recovery coefficient is the most different.Generally, Need accurately to measure velocity variations before and after collision material, collision recovery coefficient could be obtained, and it is the most difficult accurately to detect speed With carry out.Additionally, measure the jumping height change before and after collision material impacts, it also it is a kind of effectively metering system.But material The height change that collision rift is upspring is dynamic, accurately obtains the maximum height value after it is upspring the most relatively difficult, and it is measured by mistake Difference is relatively big, have impact on the computational solution precision of collision recovery coefficient.Therefore, exploitation one collision recovery coefficient is the most generally surveyed Determine method, and be generalized in industry-by-industry to apply significant.

In general, accurately measure velocity variations before and after collision material, collision recovery coefficient can be obtained.And accurately examine Degree of testing the speed typically is difficult to.Additionally, measure the jumping height change before and after collision material impacts, it also it is the one effectively side of measurement Formula.But the height change upspring after material impacts is dynamic, accurately obtain the maximum height value after it is upspring also the most tired Difficulty, have impact on the computational solution precision of collision recovery coefficient.

In view of this, the present inventor develops a kind of device based on sound wave sensing determination material impacts recovery coefficient.

Summary of the invention

It is an object of the invention to provide a kind of device and method based on sound wave sensing determination material impacts recovery coefficient, Device to test is simple, only need to be by the moment of audio frequency change corresponding during measurement collision material multiple impacts, can be accurately Obtain its collision recovery coefficient, and the measurement of time relatively tachometric survey, dynamic height measure much easier, certainty of measurement The highest, can be used for determining the collision recovery coefficient arbitrarily colliding material.

To achieve these goals, technical scheme is as follows:

A kind of device based on sound wave sensing determination material impacts recovery coefficient, including base, support, crossbeam, collision ball, Impingement plate, sound transducer, capture card and computer；

Described impingement plate and support are fixed on base, and crossbeam is rack-mount, and crossbeam is positioned at above impingement plate, touches Billiards is embedded on crossbeam, and sound transducer is arranged on impingement plate side and the position fallen near collision ball, described sound sensor Device, capture card are sequentially connected with computer；

Described collision ball is respectively adopted different collision materials and makes from impingement plate.

Described impingement plate is rectangular slab.

After using technique scheme, the work of present invention device based on sound wave sensing determination material impacts recovery coefficient is former Reason, comprises the following steps:

One, by sound transducer near collision ball drop-off positions substantially；

Two, computer is opened, the signal of monitoring sound transducer；

Three, manually allowing collision ball drop from crossbeam, note crossbeam is H with impingement plate difference in height, collides ball and falls to touch Hitting plate, collision rift is upspring, and falls in turn and again collides with impingement plate, and collision process proceeds to collide ball and stops on impingement plate Till；

Four, in collision process, capture card gathers the audio signal that sound transducer detects, and audio signal is real-time Sending to computer, computer generates display audio frequency and changes over curve；

Five, according to audio frequency change over curve calculate collision recovery coefficient:

Time and the total time of multiple impacts that can obtain collision every time curve is changed over, from audio frequency from audio frequency Change over one group of time of choosing in curve: collide the total time T of (n+1)th collision for i.e. the 1st time_nCollide with first time The total time T of this collision of end 2n+1_2n, calculate according to below equation and collide recovery coefficient:

$e={(\frac{T_{2n}}{T_n}-1)}^{\frac{1}{n}}.$

The step of above-mentioned calculating collision recovery coefficient specifically includes:

Remember the i-th-1 time and the time of i & lt collision is respectively t_i-1And t_i, corresponding collision ball whereabouts acceleration is respectively a_i-1And a_iIf collision ball the i-th-1 time and i & lt collision impingement plate corresponding speed are V_i-1And V_i, then have:

$e=\frac{V}{V_{i-1}}=\mathrm{...}=\frac{V_2}{V}---\left(1\right)$

Can be obtained by formula (1):

V_i=eV_i-1=e²V_i-2=...=eⁱV₁ (2)

WhereinFor corresponding speed during the 1st collision impingement plate of collision ball；

The time interval of the i-th-1 time collision of collision ball and i & lt collision impingement plate is Δ t_i=t_i-t_i-1, during i & lt collision Corresponding speed V_iWith time interval Δ t_iRelation be:

V_i=g Δ t_i/2 (3)

Can be obtained by formula (2) and formula (3):

${\mathrm{\Δt}}_i=\frac{2e^i{V}_1}{g}=e^i\sqrt{\frac{8H}{g}}---\left(4\right)$

From the total time colliding (n+1)th collision for the 1st time it isThen

$T_n=\underset{i=1}{\overset{n}{\Σ}}\left(e^i\right)=\sqrt{\frac{8H}{g}}\frac{1-e^n}{1-e}---\left(5\right)$

Can be obtained by formula (5):

$T_{2n}=\underset{i=1}{\overset{2n}{\Σ}}\left(e^i\right)=\sqrt{\frac{8H}{g}}\frac{1-e^{2n}}{1-e}---\left(6\right)$

Can be obtained divided by formula (6) by formula (5):

$e^{2n}-\frac{T_{2n}}{T_n}{e}^n+\frac{T_{2n}}{T_n}-1=0---\left(7\right)$

Solve formula (7) can obtain:

$e={(\frac{T_{2n}}{T_n}-1)}^{\frac{1}{n}}---\left(8\right);$

Finally choose a n value, calculate collision recovery coefficient according to formula (8).

The invention has the beneficial effects as follows: test device is simple to operation, when only need to collide material multiple impacts by measurement In the moment of corresponding audio frequency change, can accurately obtain its collision recovery coefficient, it is not necessary to height H is included in calculating, and the time Measurement relatively tachometric survey, dynamic height measure much easier, certainty of measurement is the highest, can be used for determining and arbitrarily collides material The collision recovery coefficient of material.

Below in conjunction with the drawings and specific embodiments, the present invention will be further described.

Accompanying drawing explanation

Fig. 1 is present invention apparatus structure schematic diagram based on sound wave sensing determination material impacts recovery coefficient；

Fig. 2 is that acceleration changes over curve chart；

Fig. 3 is the instance graph that acceleration changes over curve.

Label declaration

Collision ball 1, impingement plate 2, impact zone 21, sound transducer 3, capture card 4, base 5, support 6, crossbeam 7, computer 8。

Detailed description of the invention

As it is shown in figure 1, a kind of based on sound wave sensing determination material impacts recovery coefficient the device that the present invention discloses, a kind of Device based on sound wave sensing determination material impacts recovery coefficient, including base 5, support 6, crossbeam 7, collision ball 1, impingement plate 2, Sound transducer 3, capture card 4 and computer 8；Described collision ball 2 is respectively adopted different collision materials and makes from impingement plate 3, Described impingement plate 2 is rectangular slab.

Impingement plate 1 and support 6 are fixed on base 5, and crossbeam 7 is installed on the frame 6, and crossbeam 7 is positioned on impingement plate 2 Side, collision ball 1 is embedded on crossbeam 7, and sound transducer 3 is arranged on impingement plate 2 side and the position fallen near collision ball 1, i.e. Impact zone 21 on impingement plate 2, described sound transducer 3, capture card 4 are sequentially connected with computer 8.

Above-mentioned method based on sound wave sensing determination material impacts recovery coefficient, comprises the following steps:

One, by sound transducer 3 near collision ball 1 drop-off positions substantially；

Two, computer 8 is opened, the signal of monitoring sound transducer 3；

Three, manually allowing collision ball 1 drop from crossbeam 7, note crossbeam 7 and impingement plate 2 difference in height are H, collide ball 1 and drop To impingement plate 2, collision rift is upspring, and falls in turn and again collides with impingement plate 2, and collision process proceeds to collide ball 1 and stops at Till on impingement plate 2；

Four, in collision process, capture card 4 gathers the audio signal that sound transducer 3 detects, and audio signal is real Time send to computer, as in figure 2 it is shown, computer generate display audio frequency change over curve；

Five, according to audio frequency change over curve calculate collision recovery coefficient:

Time and the total time of multiple impacts that can obtain collision every time curve is changed over, from audio frequency from audio frequency Change over one group of time of choosing in curve: collide the total time T of (n+1)th collision for i.e. the 1st time_nCollide with first time The total time T of this collision of end 2n+1_2n, calculate according to below equation and collide recovery coefficient:

$e={(\frac{T_{2n}}{T_n}-1)}^{\frac{1}{n}}.$

The step of above-mentioned calculating collision recovery coefficient specifically includes:

Remember the i-th-1 time and the time of i & lt collision is respectively t_i-1And t_i, corresponding collision ball whereabouts acceleration is respectively a_i-1And a_iIf collision ball the i-th-1 time and i & lt collision impingement plate corresponding speed are V_i-1And V_i, then have:

$e=\frac{V_i}{V_{i-1}}=\mathrm{...}=\frac{V_2}{V_1}---\left(1\right)$

Can be obtained by formula (1):

V_i=eV_i-1=e²V_i-2=...=eⁱV₁ (2)

WhereinFor corresponding speed during the 1st collision impingement plate of collision ball；

The time interval of the i-th-1 time collision of collision ball and i & lt collision impingement plate is Δ t_i=t_i-t_i-1, during i & lt collision Corresponding speed V_iWith time interval Δ t_iRelation be:

V_i=g Δ t_i/2 (3)

Can be obtained by formula (2) and formula (3):

${\mathrm{\Δt}}_i=\frac{2e^i{V}_1}{g}=e^i\sqrt{\frac{8H}{g}}---\left(4\right)$

From the total time colliding (n+1)th collision for the 1st time it isThen

$T_n=\underset{i=1}{\overset{n}{\Σ}}\left(e^i\right)=\sqrt{\frac{8H}{g}}\frac{1-e^n}{1-e}---\left(5\right)$

Can be obtained by formula (5):

$T_{2n}=\underset{i=1}{\overset{2n}{\Σ}}\left(e^i\right)=\sqrt{\frac{8H}{g}}\frac{1-e^{2n}}{1-e}---\left(6\right)$

Can be obtained divided by formula (6) by formula (5):

$e^{2n}-\frac{T_{2n}}{T_n}{e}^n+\frac{T_{2n}}{T_n}-1=0---\left(7\right)$

Solve formula (7) can obtain:

$e={(\frac{T_{2n}}{T_n}-1)}^{\frac{1}{n}}---\left(8\right);$

Finally choose a n value, calculate collision recovery coefficient according to formula (8).

The following is the present invention and measure the application example of collision coefficient, COMPUTER DETECTION to audio frequency change over curve such as Shown in Fig. 3, in conjunction with table 1 and 2, have the following steps:

1) from Fig. 3 curve, take the time that front 8 audio peak are corresponding, see table 1 respectively:

Sequence number	1	2	3	4	5
						Time (s)	1.634	2.048	2.349	2.576	2.757
Sequence number	6	7	8	9
						Time (s)	2.903	3.027	3.128	3.216

2) time interval Δ t corresponding to 8 time is calculated from Fig. 3_i；

Sequence number	1	2	3	4
					Time interval Δ ti	0.414	0.301	0.227	0.181
Sequence number	5	6	7	8
					Time interval Δ ti	0.146	0.124	0.101	0.088

3) basisMake n be respectively 4 and 8, T can be calculated₄=1.123 and T₈=1.582

4) basisMaking n=4, can calculate e is 0.7996.

These are only the specific embodiment of the present invention, the not restriction to protection scope of the present invention.All setting according to this case The equivalent variations that meter thinking is done, each falls within the protection domain of this case.

Claims (2)

1. a device based on sound wave sensing determination material impacts recovery coefficient, it is characterised in that: include base, support, horizontal stroke Beam, collision ball, impingement plate, sound transducer, capture card and computer；

Described impingement plate and support are fixed on base, and crossbeam is rack-mount, and crossbeam is positioned at above impingement plate, collide ball Being embedded on crossbeam, sound transducer is arranged on impingement plate side and the position fallen near collision ball, described sound transducer, adopts Truck is sequentially connected with computer；

Described collision ball is respectively adopted different collision materials and makes from impingement plate.

A kind of device based on sound wave sensing determination material impacts recovery coefficient, it is characterised in that: Described impingement plate is rectangular slab.