CN105180887A - Wide span beam deflection deformation measuring method - Google Patents

Abstract

The invention provides a wide span beam deflection deformation measuring method, comprising setting a displacement sensor parallel with an object to be detected, and a displacement sensor perpendicular to the object to be detected at lower ends of the object to be detected; fixing the displacement sensor parallel with the object to be detected, and moving the displacement sensor perpendicular to the object to be detected, wherein the data of the displacement sensor parallel with the object to be detected is the horizontal ordinate value of each data points of a deflection curve, used for determining the X-axis ordinate value of a current measuring point, and the data of the displacement sensor perpendicular to the object to be detected is the longitudinal coordinate value of each data point of the deflection curve; a horizontal ordinate value and a longitudinal coordinate value form a data point on the deflection curve, used for measuring the deflection deformation value measured by the current measuring point; and a computer obtaining and fitting the data measured by the two sensors to draft a continuous deflection curve. The method realizes deflection curve accurate fitting through the two sensors, has the characteristics of low measurement cost and high test precision, and can realize continuous measurement at span intervals.

Description

A method for measuring the deflection of long-span beams

technical field

The invention relates to a method for measuring deflection deformation, in particular to a method for measuring deflection deformation of a large-span beam after being loaded.

Background technique

Large-span beams with simply supported or fixed supports at both ends will deflect and deform after being subjected to self-weight or external loads, and the amount of deflecting deformation depends on the stiffness of the beam. This stiffness value is one of the important parameters reflecting the mechanical properties of structural parts. In order to measure the stiffness of long-span structural members, it can be judged by measuring the amount of deflection deformation. For example, when the car body structure is subjected to vertical loads, the longitudinal beams of the car body will be deflected and deformed. In order to study the static stiffness performance of the body structure, it is necessary to measure the deflection curves of the longitudinal members.

The existing measurement method is to arrange a certain number of displacement sensors at intervals at the lower end of the longitudinal beam, and to fit the deflection curve of the longitudinal beam by measuring the deformation of these discrete measuring points. This measurement method needs to arrange a large number of displacement sensors, and is limited by the number of sensors arranged, so it is impossible to accurately obtain the deflection curve of the longitudinal beam of the vehicle body.

Contents of the invention

The object of the present invention is to provide a deflection deformation measurement method and detection device with low measurement cost, high measurement accuracy, and continuous measurement in the span interval, so as to solve the problem of deflection measured by a large number of displacement sensors that need to be arranged in the existing method. Curve inaccuracy problem.

In order to achieve the above object, technical scheme of the present invention is as follows:

A method for measuring the deflection of a large-span beam, the method is to arrange a displacement sensor parallel to the measured object and a displacement sensor perpendicular to the measured object at the lower end of the measured object, so that the displacement sensor parallel to the measured object Fixed, moving the displacement sensor perpendicular to the measured object, the data of the displacement sensor parallel to the measured object is the abscissa value of each data point on the deflection curve, which is used to judge the X-axis coordinate value of the current measuring point, vertical The displacement sensor data of the measured object is the ordinate value of each data point on the deflection curve, and the two coordinate values constitute each data point on the deflection curve, which is used to measure the deflection measured at the current measuring point. The computer acquires the data measured by the two sensors and fits them to draw a continuous deflection curve.

The method realizes the accurate fitting of the deflection curve through two displacement sensors, and obtains the result that the traditional measurement method requires countless displacement sensors. The measurement cost is low, the measurement accuracy is high, and the continuous measurement in the span interval can be realized.

Description of drawings

Fig. 1 is the measurement schematic diagram of the method of the present invention; Wherein 1 is the measured object, 2 is the displacement sensor parallel to the measured object, 3 is the displacement sensor perpendicular to the measured object, and 4 is the distance between the AB measuring points deflection curve.

Fig. 2 is a kind of automatic detection device that realizes this method; wherein 5 is a driving motor, 6 is a limit photoelectric switch, 7 is a baffle plate, 8 is a guide rail, 9 is a ball screw, and 10 is a movable workbench.

Detailed ways

Further illustrate the present invention below in conjunction with accompanying drawing:

As shown in Figure 1, the measured object 1 is subjected to the effect of the external load F, and deflection will occur. In order to measure the deflection curve between the spans AB, the method of the present invention is to arrange a The displacement sensor 2 of the measured object and a displacement sensor 3 perpendicular to the measured object, the displacement sensor 2 parallel to the measured object is fixed at point A, and the sensor 3 perpendicular to the measured object is moved between points A and B, At this time, the displacement sensor 2 parallel to the measured object can determine the current position of the displacement sensor 3 perpendicular to the measured object, and the displacement sensor 3 perpendicular to the measured object measures the deflection deformation of the current measuring point C. The data pair measured by the sensors 2 and 3 is returned to the computer, and drawn in the XOY coordinates, the deflection curve 4 between the AB measuring points of the measured object 1 can be obtained.

The method of the present invention can be realized with a fully automatic measuring device. As shown in Figure 2, the device consists of a drive motor 5, a guide rail 8, a ball screw 9, a movable workbench 10, a first displacement sensor 2, a second displacement sensor 3 and a computer; the drive motor 5 is connected to drive the ball screw 9, The movable workbench 10 is installed on the ball screw 9 and cooperates with the guide rail 8 to move along the guide rail. The first displacement sensor 2 is fixed on the end of the guide rail 8 and installed parallel to the measured object. The second displacement sensor 3 is fixed On the movable workbench 10, it is installed perpendicular to the measured object; the first displacement sensor 2 and the second displacement sensor 3 are connected to the computer signal.

The device can realize the automatic movement of the displacement sensor 3 perpendicular to the measured object. When working, the computer controls the drive motor 5 to rotate, and drives the ball screw 9 to rotate, thereby driving the movable worktable 10 to move on the guide rail 8. linear motion. During measurement, the data returned to the computer by the displacement sensor 2 parallel to the measured object is the abscissa value of each data point on the deflection curve 4; the data returned to the computer by the displacement sensor 3 perpendicular to the measured object is the deflection curve The ordinate value of each data point on 4; the two constitute each data point on the deflection curve 4. During work, during the slow movement of the movable worktable 10, the sensors 2 and 3 continuously return measurement data to the computer, and these coordinate points are plotted on the plane coordinate XOY to obtain an accurate deflection curve 4 by fitting. In order to accurately measure the deflection curve 4 between the spans AB and ensure the safety of the test equipment, baffles 7 are installed at both ends of the guide rail 8, and a limit photoelectric switch 6 is installed on each of the baffles 7 at both ends. The limit points of the sensing area of the bit photoelectric switch 6 are adjusted to point A and point B of the measurement span. During measurement, when the movable workbench 10 reaches the two limit points A and B of the measurement interval, and enters the sensing area of the limit photoelectric switch 6, the photoelectric switch outputs a switching signal, which is input to the drive motor controller, Thereby control drive motor 5 stops rotating.

Claims (3)

1. a long-span beam deflection deformation measuring method, described method arranges displacement transducer and a displacement transducer perpendicular to measurand being parallel to measurand, the displacement transducer being parallel to measurand is fixed, the mobile displacement transducer perpendicular to measurand, the data being parallel to the displacement transducer of measurand are the abscissa value of each data point on deflection curve, for judging the X-axis coordinate figure of current measuring point, displacement transducer data perpendicular to measurand are the ordinate value of each data point on deflection curve, namely two coordinate figures constitute each data point on deflection curve, for measuring the deflection deformation value that current measuring point records, computing machine obtains the data matching that two sensors record, continuous print deflection curve can be drawn.

2. a long-span beam deflection deformation measurement mechanism, it is characterized in that, device is by drive motor (5), guide rail (8), ball-screw (9), movable working platform (10), the first displacement transducer (2), second displacement sensor (3) and computing machine; Drive motor (5) connects driving ball-screw (9), movable working platform (10) is arranged on ball-screw (9), and coordinate with guide rail (8), can move along guide rail, first displacement transducer (2) is fixed on the end of guide rail (8), be parallel to measurand to install, second displacement sensor (3) is fixed on movable working platform (10), perpendicular to the installation of measurand; First displacement transducer (2) is connected with Computer signal with second displacement sensor (3).

3. long-span beam deflection deformation measurement mechanism according to claim 1, it is characterized in that, also comprise limiting photoelectric switch (6) and plate washer (7), at guide rail (8) two ends, baffle plate (7) is installed, baffle plate (7) is respectively provided with a limiting photoelectric switch (6), the induction region limit point of limiting photoelectric switch (6) is adjusted to the A point and B point of measuring span, the on-off model that limiting photoelectric switch (6) exports is transfused to drive motor controller, thus control drive motor (5) stops operating.