FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION Apparatus for multi-axis testing of rigid body cargo vehicles APPLICANTS TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India INVENTORS Mr. Dwivedi Vivek, Mr. Santosh Gosavi Mr. Chimad Mahavir, Mr. Mithun Chaskar Mr. Pradeep Mamgain, Mr. Ganesh Kale and Mr. Shrikrishna Joshi AH are Indian Nationals of TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed. FIELD OF INVENTION This invention generally relates to the apparatus for testing the vehicles and more particularly it relates to apparatus for Full Frame Fatigue testing of vehicles. The present invention is the modification of the invention claimed in the specification of the main Indian Patent applied under IP A No.- 2121/MUM/2011. BACK GROUND OF THE INVENTION Frame is the back bone of a vehicle. A frame of a vehicle should withstand predetermined period of service life, for example: 1 Million Kilometers. Hence it is necessary to validate the life span of the frame with intended loading on service road to meet the said requirement. Generally two kind of accelerated testing methodology is available for validating the frame of the vehicles. In one kind of methodology, the test vehicle is made to run on torture track using derived torture track pattern. This kind of Test of running the vehicles in torture track takes at least 3 years to validate a Frame of vehicle for predetermined period of service life for example: 1 Million Kms. second kind of methodology is by using the six poster simulator for testing the frame of the vehicles. The six poster simulator method is used for generating fairly higher acceleration levels, but six poster testing simulates only vertical wheel loads, which in turn simulates 50 to 60 % damage on frame of the vehicles and other structural aggregates. The six poster testing method of the vehicle requires a completely built vehicle which is held on six posters in the form of fixtures having provision to hold the wheels and to apply the forces only in the vertical direction by means of actuators. The Dead Load is put in the Load body and the vertical excitation is given at each wheel. So it is required to build the complete vehicle with Load body for six poster testing. This setup becomes quite bulky especially for tractor trailer kind of vehicles. So an alternate setup is required to validate the frame of vehicles with higher acceleration and fairly accurate damage simulation. This can be achieved using damage editing for acceleration and applying all kinds of Load at each wheel end for accurate response simulation. It is also possible to simulate the other structural aggregates which are in the Chassis Load path such as - Wheel ends, Axles, springs and Load body connections. To simulate the inertial effects of heavy overhung masses on frame, the same aggregates can also be attached on frame of vehicle during the testing. Hence new apparatus is devised to load the chassis frame without using Load body or trailer to reduce the overall size of test setup. Also, Instead of using the dead load in the Load body, the chassis is restrained in vertical directions and the load is applied through each wheel to create similar effect of Loading on chassis. The similar concept of data acquisition & damage editing as in 4 posters can be used here. As we want to apply loads in each direction at wheels, multidirectional data in each direction need to be acquired. Hence the efforts are put to develop th