Title of Invention

A MULTI CHANNEL AUTOMATED STATIC LOAD TESTING MACHINE

Abstract

The multi channel load testing machine has a master unit connected to a hydraulic power pack and pressure distributing manifold. The master unit consists of activators load cells and displacement measuring means. Additional activators and displacement measuring means are provided below a loading ramp with load cells at predetermined points multi channel converters connect the activators and the master unit assembly to a PC with a printer. Relay means are provided to deactivate the unit when necessary.

Full Text

This invention relates to a multi channel automated static lead testing machine. The expression static in this disclosure includes slowly varying leads as well Structures that are subject to acceleration and/or wind leads are normally tested for load carrying capability to evaluate the mechanical properties of such structures. Static load testing is conducted on aerospace, automobile and ground structures. The loads applied during testing may be static or quasi static in nature. Conventionally, loads are simulated by centrifuge testing or by test rig method. Multi channel static load testing machines hitherto known in the art use individually controlled servo loading activators. Leading pattern in all the jacks being the same, individual control or variation of loads at desired points poses problems. The object of this invention is to avoid the drawbacks of the existing load testing marlins. The modular multi channel testing machine developed by us uses indigenously by available components ensuring low cost of construction. Another object of this invention is to enable load testing simultaneously at various points under predetermined load condition. The load testing machine has master unit for distributing the desired pressure or load to the structure to be tested. This master unit consists of a loading frame with at least one activator, at least one means such as vernier for distance measuring a load cell and their interface units. The master unit is connected to additional units of activators, distance measuring means, and load cells. Load cells measure the loads applied at the final loading point on the structure to be tested. Displacement of the activators an application of loads are indicated by the distance measuring means. The master unit alongwith additional activators, distance means such as digital output vernier calipers and the load cells are connected to a PC provided with a printer. Multi channel converters are provided for multiplying the available number of parallel and serial ports in the PC, Relay means are also connected to deactivate the unit if the load carrying capacity exceeds a predetermined level or when the structure to be tested shows signs of strain, collapse or other anomalies. The machine is also provided with known means for measuring structural displacement and means for monitoring linkage load distribution of the load cells. These means are connected to the multi channel converter and through that to the PC for data acquisition. A load ramp provided with adjustable held-periods at predetermined or specific load levels is also provided for. The pressure distribution manifold connected to the activators are also provided with lever arrangement for adjusting the load levels to the desired value. Diameters of the additional activators may be varied to regulate the load applied at the final test point. Relays provided in the machine are deactivated by three types of abort mechanisms incorporated therein. Since the machine is operated and controlled by a PC, suitable software may be fed thereto to deactivate the relay if the load and the displacement exceed the predetermined limit, known hardware may be provided to check the feed back values from the activators with the maximum set limit and to deactivate or abort the relay whenever necessary. In addition, it is also possible to manually abort the machine by switching off when the data acquired demands deactivation. The multi channel automated static load testing machine according to this invention comprises a multi channel automated static load testing machine comprising a master unit for applying load or pressure consisting of at least one activator provided with distance measuring means to indicate the activator displacement and a load cell, the said master unit being connected to a hydraulic power pack provided with valve means, and a pressure distributing manifold connected to a plurality of additional activators with distance measuring means and load cells located below a loading ramp to house the structure to be tested, the said master unit, the said additional activators and the said load cells being connected through at least one multi channel converter to obtain displacement data of the structure when a predetermined load is applied thereon, and at least one relay means being provided for deactivating the said master unit. The invention will now be described with particular reference to the single figure in the accompanying drawing. The master unit is represented by MU, the hydraulic power pack, with valve means by the letters P V and the pressure manifold by P M. The valve may be a macaroni hydraulic valve disclosed in our Indian Patent No. 182069. Additional activators connected to the master unit and the pressure manifold assembly are represented by 2 to 6 and the distance measuring means are represented by V2 to V6. In a preferred embodiment, the distance measuring means are vernier capable of digital display. Load cells are indicated by LC2 to LC6. Multi channel converters MCI to MC3 are connected to the activators, master unit assembly and to the PC with a printer P. Relay means capable of deactivating the system is represented by R. The structure to be tested is mounted on a ramp above the load cells and is shown by the reference letter S. Loads on the different activators may be varied either by means of a lever (not shown in the figure) or by varying the diameter of the activator. The master unit and the relay means may be programmed by appropriate software. The machine is made with indigenous components that are commercially available. The PC based system facilitates easy data acquisition, analysis, data plots and data tables. Yet another advantage is that the machine can operate at low pressure resulting in low heat generation. Even though a specific embodiment has been described herein above, obvious equivalent known to persons skilled in the art are not excluded from the scope of the invention and the appended claims. WE CLAIM: 1. A multi channel automated static load testing machine comprising a master unit (MU) for applying load or pressure consisting of at least one activator provided with distance measuring means (V2 to V6) to indicate the activator displacement and a load cell (LC2 to LC6) the said master unit being connected to a hydraulic power pack (PV) provided with valve means, and a pressure distributing manifold (PM) connected to a plurality of additional activators (2 to 6) with distance measuring means (V2 to V6) and load cells (LC2 to LC6) being located below a loading ramp to house the structure to be tested, the said master unit (MU), the said additional activators (2 to 6) and the said load cells (LC2 to LC6) being connected plough at least one multi channel converter (MCI to MC3) to obtain displacement data of the structure when a predetermined load is applied thereon, and at least one relay means (R) being provided for deactivating the said master unit (MU). 2. The multi channel automated static load testing machine as claimed in claim 1, wherein the said distance measuring means are vernier provided with digital display. 3. The multi channel automated static load testing machine as claimed in claims 1 and 2, wherein the said valve means of the said hydraulic power pack (PV) is a mechatronic hydraulic valve. 4. The multi channel automated static load testing machine as claimed in any one of the previous claims, wherein the diameters of the said additional activators (2 to 6) are the same. 5. The multi channel automated static load testing machine as claimed in claims 1 to 3, wherein the diameters of said additional activators (2 to 6) are different, 6. The multi channel automated static load testing machine as claimed in claims 1 to 5, wherein the said additional activators (2 to 6) are provided with known leverage means to regulate the load or pressure. 7. The multi channel automated static load testing machine as claimed in any of the previous claims, wherein the said relay means (R) is provided with a programmed PC to control and abort the loading testing. 8. The multi channel automated static load testing machine as claimed in claims 1 to 6, wherein the said relay means (R) is a mechanically operable relay to abort the load testing manually. 9. The multi channel automated static load testing machine as claimed in claim 6, wherein the said programmed PC is connected to a printer. 10. A multi channel automated static load testing machine, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

1356-mas-1995 abstract.jpg

1356-mas-1995 abstract.pdf

1356-mas-1995 claims.pdf

1356-mas-1995 correspondence-others.pdf

1356-mas-1995 correspondence-po.pdf

1356-mas-1995 description (complete).pdf

1356-mas-1995 drawings.pdf

1356-mas-1995 form-1.pdf

1356-mas-1995 form-26.pdf