Vibration Testing and Simulator

The vibration simulator machine is designed to scientifically simulate the vibrations and jolts subjected to various filled containers during the transportation, within the laboratory. The machine is based on the guidelines provided an ASTM D-999, TAPPI T-817-pm, and IS7028 (part II). The packages (containers) intended for transportation of goods is required to fulfill the primary function of physical protection to the content within it. Normally the transportation is by road, rail, sea and air - in singular or in various combinations of these modes. Due to these the package is subjected to the various vibrations and jolts of varying intensities. It is very difficult to simulate these vibrations in totality, however, the machine is designed to simulate these conditions closely in the laboratory. The vibration test provides means to determine in advance, under standard laboratory conditions, how a filled package will fare in a given distribution system. This test is used to assess the performance of containers only, in terms of its strength and the protection that it provides to the content, when subjected to the vibrations during the transportation. The Machine: The machine is rigidly fabricated from mild steel structure. The upper tabletop is suspended for vibration by bearing blocks. The fixed amplitude of 25mm is generated using cam assembly. The frequency of vibration can be varied using the panel box from 2 Hz to 10 Hz. The machine can generate the vibrations in three modes viz.

• In phase vibrations, that is, both the cam assembly is in phase and the tabletop ends moves simultaneously.
• 90 Deg out of phase, that is the cam assembly are 90 degrees out of phase with each other. One end of the table moves 90 degrees out of phase with respect to the other.

The goods manufactured are subjected to various types of vibrations, primarily generated due to rotating, pulsating or oscillating forces generated by handling of the material and by vehicular transport. The component or equipment may fail or malfunction, due to these vibrations, at the customer's end. Vibration simulation is the technique use to simulate these vibration conditions for testing of component or equipment, in the factory, before final despatch. A typical equipment consists of a vibrating table, the controller and the sensor. The equipment to be tested is mounted on the vibrating table. The vibrating table generates the sinusoidal vibration when fed with variable frequency through the controller. The state of vibration is sensed through a sensor and the signal is fed back to the controller to simulate the conditions as required. Various testing profiles are possible like, linear, logarithmic, random, octave etc. The entire testing process parameters can be logged with respect to time for quality assurance. Applications:

• Electronic and Electrical Instruments for reliability & fatigue testing.
• Automobile components and assemblies for resonance testing.
• Packaging and Packages for simulation of transport conditions.

The majority of welded structures, castings, forgings and other fabricated of machined parts contained residual stress because of the different thermal gradient associated with the work piece. The existence of these residual stress is undoubtedly the cause of dimensional instability. The equipment STREL-Q is a portable VSR equipment. A typical STREL-Q equipment consist of an electro mechanical vibration exciter unit, and electronic vibration controller with monitor, a chart recorder, the vibration sensor and rubber cushion and clamps. The typical operation time can be maximum one hour for most jobs, irrespective of size, shape or weight of the job. Theory of VSR technique: Stress relieving by any method is associated with micro plastic deformation of atoms. These is achieved by injecting additional energy. In VSR technique the vibrations in the form of mechanical energy is injected into the work piece. This applied energy is super imposed on the existing residual stresses. Because of this the resultant stress energy crosses the yield boundary, and hence the material undergo micro plastic deformation effecting reduction of residual stress value. Advantages:

• VSR causes no metallurgical changes, and does not reduce yield strength, tensile strength of fatigue life, as in the case of thermal stress relieving (TSR).
• The equipment is portable and simple to operate. The material handling cost are drastically reduced by bringing the process to the work piece.
• The operating cost are dramatically reduced as very little power and time are consumed as compared to TSR.
• The VSR technique can be used on any size, shape or weight of work piece. No change in the equipment is needed.
• No undesirable side effects, such as oxidation or scaling as in the case of TSR.
• Design and developed under license from CMTI, recognised Government of India research organisation.

Vibratory finishing equipment uses a bowl mounted on a sturdy frame. The component to be processed are loaded into the bowl along with the special deburring media and finishing chemical. The bowl is then vibrated to generate the spiral motion of media and material to achieve the required finish. These machines are widely used for:

• Deburring
• Degreasing
• Polishing
• Cleaning of pressed parts
• Forged Parts
• Machined Parts
• Cast Parts
• Jewellery Parts

Features:

• The process is much faster than tumbling or barreling due to 100% cycle time utilization.
• The motion is gentle hence delicate parts can be processed without any distortion.
• Easy and fast loading and unloading with the possibility of stage inspection for better overall process control.
• Finishing chemicals can be recirculated to achieve the best results.
• The machine can be given with automatic media separation facility.

Various standard models are available from bowl volume capacity of 20ltrs to 600 liters.