Effect of Load variation and thickness on deflection and operating stress of wave spring

Wave springs are used for load bearing into assemblies. When force applied to the spring, load is gradual or abrupt. Typically wave spring will occupy an extremely small space after compressions. In this paper effect of change in thickness of wave spring o the deflection of spring and on operating stress is studied. This study leads towards the impact of thickness change under different load condition. The result reveals that after increasing the thickness from 0.1181 to 0.23622 inch, drastically decrement in the deflection as well as operating stress for different loading condition in wave spring. Study shows the deflection for two different spring materials (nickel and beryllium copper) considering different parameters that help to choose best spring material.


INTRODUCTION
Spring is made up of elastic material as after getting compressed it stored the energy. Generally springs are made of steel. The spring constant of a spring can be defined as the change in the force it exerts, divided by the change in deflection, so spring rate is described by unit N/m. in case of torsion spring, when it is twisted about its axis by an angle, it produces a torque proportional to the angle and spring's rate having unit Nm/rad. wave springs replaced helical springs because wave springs required less height compare to coil spring for the similar load application. Wave springs were first discovered by Smalley industries of USA in 1990's. They manufacture wave spring of many types. Small springs can be wound from pre @ IJTSRD | Available Online @ www.ijtsrd.com | Volume -2 | Issue -4 | May-Jun Wave springs are used for load bearing into assemblies. When force applied to the spring, load is gradual or abrupt. Typically wave spring will occupy an extremely small space after compressions. In this paper effect of change in thickness of wave spring on the deflection of spring and on operating stress is studied. This study leads towards the impact of thickness change under different load condition. The result reveals that after increasing the thickness from 0.1181 to 0.23622 inch, drastically decrement noticed in the deflection as well as operating stress for different loading condition in wave spring. Study shows the deflection for two different spring materials (nickel and beryllium copper) considering different ing material.
wave spring thickness, Deflection, working Spring is made up of elastic material as after getting compressed it stored the energy. Generally springs are constant of a spring can be defined as the change in the force it exerts, divided by the change in deflection, so spring rate is described by unit N/m. in case of torsion spring, when it is twisted about its axis by an angle, it produces a torque nal to the angle and spring's rate having unit Nm/rad. wave springs replaced helical springs because wave springs required less height compare to coil spring for the similar load application. Wave springs were first discovered by Smalley industries of in 1990's. They manufacture wave spring of many types. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication. Some non-ferrous metals are also used including phosphor bronze and titanium for parts requiring corrosion resistance and beryllium copper for springs carrying electrical current. Common spring materials include stainless steel, alloy steels, carbon steels, non materials and some super-alloys which exist in the market with preparatory designations and nomenclature. Each spring material has diverse compositions, individual properties and also for a particular type of spring, more than one feasible alternative spring materials may be available in the market.

1.1
Wave spring: Among the many types of springs, wave springs have attracted considerable attention this kind of long and reliable source of long lasting durability and considerable effectiveness than rest of the springs. Wave springs are used to reduce the height of spring and to produce the same end effect end that of a coil spring. Wave springs operate as load bearing devices. They take up play and compensate for dimensional variations within assemblies. A virtually unlimited range of forces can be produced whe loads build either gradually or abruptly to reach a predetermined working height. This establishes a precise spring rate in which load is proportional to deflection. Functional requirements are necessary for both dynamic and static spring applications performance characteristics are individually built into each spring to satisfy a variety of precise operating conditions. Typically, a wave spring will occupy an Jun

Scientific (IJTSRD)
International Open Access Journal on deflection and operating stress of wave spring hardened stock, while larger ones are made from annealed steel and hardened after fabrication. Some ferrous metals are also used including phosphor titanium for parts requiring corrosion resistance and beryllium copper for springs carrying electrical current. Common spring materials include stainless steel, alloy steels, carbon steels, non-ferrous alloys which exist in the ket with preparatory designations and nomenclature. Each spring material has diverse compositions, individual properties and also for a particular type of spring, more than one feasible alternative spring materials may be available in the Among the many types of springs, wave springs have attracted considerable attention this kind of long and reliable source of long lasting durability and considerable effectiveness than rest of the springs. Wave springs are used to reduce the height of the spring and to produce the same end effect end that of a coil spring. Wave springs operate as load bearing devices. They take up play and compensate for dimensional variations within assemblies. A virtually unlimited range of forces can be produced whereby loads build either gradually or abruptly to reach a predetermined working height. This establishes a precise spring rate in which load is proportional to deflection. Functional requirements are necessary for both dynamic and static spring applications. Special performance characteristics are individually built into each spring to satisfy a variety of precise operating conditions. Typically, a wave spring will occupy an International Journal of Trend in Scientific Research and Development (IJTSRD) ISSN: 2456-6470 Page: 685 extremely small area for the amount of work it performs. The use of this product is demanded, but not limited to tight axial and radial space constraints.

Wave spring types:
Gap type wave spring has gap between two ends. Continued deflection causes the gap ends to move closer together while the outer dia. presses against the bore [ fig. 1(a)]. Overlap type has overlapping ends and ends are free to move circumferentially during compression [ fig. 1(b)]. Crest-to-Crest wave spring has more numbers of turn. No need to use key between springs because the spring is integrally formed. Crest springs replaced helical spring because crest springs can develop similar forces so occupy less the axial space and solid height [ fig. 1(c)]. Nested Wave Springs are pre-stacked in parallel from one continuous filament of flat wire used for higher load. Nested springs result in a spring rate that increases proportionally to the number of turns [ fig. 1(d)].
Wavo wave spring has round-section and used for high load application and give accurate spring rate [ fig. 1(e)]. In linear wave spring forces act linearly or radially depending on the installed position and axial pressure is obtained by laying the spring flat in a straight line [ fig. 1(f)].

Spring materials and their properties:
For manufacturing of spring the material is selected by considering many parameters like spring is made of a material which having elasticity for storage of energy after compression, higher yield strength, etc. Also material must be compatible with the environment and withstand effects of temperature and corrosion without an excessive loss in performance because corrosion and temperature decrease spring reliability. Engineer must analyze about the compression rate of the spring and tensile strength for fatigue frailer and life cycle of the spring. According to the requirements of the material different materials with their properties are shown in table 1.     Table 4 calculation of operating stress and deflection for 1000lbs   Operating stress for 1000lbs spring calculation conclude that as the wave increase the frequency of the spring will decrease and also chart shows the frequency versus wave of spring for two different load. Here rapid decrement of frequency from 1000lbs to 600 ng, frequency versus no. of active coil chart shows that as the no. of active coil decrease frequency also decrease.
 For nickel and beryllium copper wave spring, the result shows that the deflection occur at maximum level in the case beryllium copper havi 11.16834093 on load of 1000 lbs  For better properties metal matrix composite can be preferred for the future scope. For nickel and beryllium copper wave spring, the result shows that the deflection occur at maximum level in the case beryllium copper having value 11.16834093 on load of 1000 lbs For better properties metal matrix composite can be preferred for the future scope.