فی توو

مرجع دانلود فایل ,تحقیق , پروژه , پایان نامه , فایل فلش گوشی

فی توو

مرجع دانلود فایل ,تحقیق , پروژه , پایان نامه , فایل فلش گوشی

استاندارد ASTM G181 در خصوص Conducting Friction Tests of Piston Ring and Cylinder Liner Materials Under Lubricated Conditions

اختصاصی از فی توو استاندارد ASTM G181 در خصوص Conducting Friction Tests of Piston Ring and Cylinder Liner Materials Under Lubricated Conditions دانلود با لینک مستقیم و پر سرعت .

استاندارد ASTM G181 در خصوص Conducting Friction Tests of Piston Ring and Cylinder Liner Materials Under Lubricated Conditions


استاندارد ASTM G181 در خصوص Conducting Friction Tests of Piston Ring and Cylinder Liner Materials Under Lubricated Conditions

 

استاندارد ASTM G181

در خصوص

Standard Test Method for

Conducting Friction Tests of Piston Ring and Cylinder Liner Materials Under Lubricated Conditions

نسخه 2011

10 صفحه

 

Scope
1.1 This test method covers procedures for conducting
laboratory bench-scale friction tests of materials, coatings, and
surface treatments intended for use in piston rings and cylinder
liners in diesel or spark-ignition engines. The goal of this
procedure is to provide a means for preliminary, cost-effective
screening or evaluation of candidate ring and liner materials. A
reciprocating sliding arrangement is used to simulate the
contact that occurs between a piston ring and its mating liner
near the top-dead-center position in the cylinder where liquid
lubrication is least effective, and most wear is known to occur.
Special attention is paid to specimen alignment, running-in,
and lubricant condition.
1.2 This test method does not purport to simulate all aspects
of a fired engine’s operating environment, but is intended to
serve as a means for preliminary screening for assessing the
frictional characteristics of candidate piston ring and liner
material combinations in the presence of fluids that behave as
use-conditioned engine oils. Therefore, it is beyond the scope
of this test method to describe how one might establish
correlations between the described test results and the frictional
characteristics of rings and cylinder bore materials for specific
engine designs or operating conditions.
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
standard.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 

 

 

 


دانلود با لینک مستقیم


استاندارد ASTM G181 در خصوص Conducting Friction Tests of Piston Ring and Cylinder Liner Materials Under Lubricated Conditions

Passive Control of Steel Structures Utilizing Cylindrical Friction Dampers

اختصاصی از فی توو Passive Control of Steel Structures Utilizing Cylindrical Friction Dampers دانلود با لینک مستقیم و پر سرعت .

Passive Control of Steel Structures Utilizing Cylindrical Friction Dampers


Passive Control of Steel Structures Utilizing Cylindrical Friction Dampers
نویسند‌گان:
[ h Mirzaeefard ] - M.Sc. Graduate, Department of Civil Engineering, K.N. Toosi University of Technology, Tehran, Iran,
[ h.r samani ] - Instructor, Department of Civil Engineering, Islamic Azad University – Pardis Branch, Tehran, Iran
[ m mirtaheri ] - Associate Professor, Department of Civil Engineering, K.N. Toosi University of Technology, Tehran, Iran

خلاصه مقاله:

In this investigation, seismic response of steel structures utilizing Cylindrical Frictional Dampers (CFD) is studied. CFD is an innovative frictional damper which comprises two principal elements, the shaft and the hollow cylinder. These two elements are assembled such that one is shrink-fitted inside the other. If the damper’s axial force overcomes the static friction load, the shaft inside the cylinder will move and results in considerable mechanical energy absorption. To assess the efficacy of CFD, various steel frames are constructed and analyzed using OpenSees software. Nonlinear time history analyses and Incremental Dynamic Analysis (IDA) are applied to the frames and clear distinction has been drawn between the frames comprising CFD and the counterparts without CFD to emphasize the effectiveness of CFD in altering seismic responses. The results show that CFD extremely improves the seismic response of the structure

کلمات کلیدی:

Passive control, Cylindrical Frictional Damper, Incremental Dynamic Analysis, Seismic response


دانلود با لینک مستقیم


Passive Control of Steel Structures Utilizing Cylindrical Friction Dampers