ABS INCLINOMETER CASING TEST REPORT 1999. 11. 21 Dong-A Geo van Co.,Ltd
INTRODUCTION Main feature of ABS tubes • Non-corrosion plastic agent • Flexible than Aluminum tube • High impact strength and light weight • Strong support by 400mm long length coupling Site Operation Fig Cross-Section (Section “A-A”) A A
CAUSE OF DAMAGE PHENOMENON • ABS inclinometer casing damaged by external force : As the misalignment of borehole and ABS inclinometer casing during installation, it happened big radial stress to the casing. Sometimes soft soil layer (ex, silt or sand) would affect lateral movement excessively. • ABS inclinometer casing damaged by axial force : Due to too much load to the top edge part of casing , The casing would be broken by axial direction. Broken by external stress Applied load to install casings Broken to the axial direction
ABS RESIN TEST RESULT Mechanical Properties MPA MPA % MPA % MPA MPA ㎜ J/m J/m Tensile Modulus Stress at Yield Strain at Yield Stress at Break Strain at Break Flexural Modulus Flexural Strength Flexural Strain Impact strength notch Izod Impact strength notch Izod Hardness Rockwell Coefficient of friction1 ASTM D638 1mm/min 50mm/min 50mm/min 50mm/min 50mm/min ASTM D790 2.8mm/min 2.8mm/min 2.8mm/min ASTM D256 . ¼″ 23℃ ASTM D256 . ¼″ 0/－30℃ ASTM D785 . R ASTM D2240 2215 1910 47 39 3.0 2.8 34 27 11 32 2150 62 11.0 265 236/119 110.0 Physical Properties 1.07 Specific gravity Melt flow rate Water absorption ASTM D792 ASTM D1238 230℃ / 38N ASTM D570 ㎤/gm g/10min % 1.050 Remark) BASF Lab test result
PROCESSING Processing Properties /Extrusion Min Max ℃ ℃ ℃ ℃ Bar Bar Bar ㎝/㎝×10-³ ℃ hr ℃ rpm Barrel temp. rear Barrel temp. mid Barrel temp. front Die temp Injection pressure Holding pressure Back pressure Mold shrinkage Mold temperature Recommended drying time Material drying temp Screw Speed 200 220 210 220 220 230 220 230 0.0077 2 70 ASTM D955 Remark) BASF Lab test result
PRODUCT ANALYSIS • Specimen : Outer Diameter Φ70, Thickness 4.0 mm ABS Inclinometer Casing • Analysis model : The cross-section of casing is symmetry. To record data after applied force equally to the 1/4 casing section. Refer to below Fig. • Applied force : External distribution force from 3bars ~ 16 bars to 1/4 casing section. • Evaluation : Checked maximum endurance break point of casing wall when the applied force being given. • Analysis Tool • Modeler :Hyper Mesh Ver 3.0 • Analysis Code : ABAQUS/Standard Ver 5.8 Applied force <tube cross-section> <1/4 specimen section>
ANALYSIS RESULT I Deformation Shape Before deformation (Red color) After deformation • Input pressure : 16 bar • Max Deformation : 0.3 mm
ANALYSIS RESULT II VON-MISES Stress Distribution Stress concentration Area • Input pressure : 16 bar • Max Stress : 4.78 kgf/mm2
ANALYSIS RESULT III Deformation - Stress Curve Stress concentration (kgf/mm2) ( X axial deformation in maximum deformation area)
ANALYSIS RESULT IV VON MISES STRESS (kg/cm2) • This graph shows maximum stress to the casing in the interval of 3bars.
CONCLUSION • This report is to write maximum endurance break point of casing wall when the applied force being given under same conditions. • → ABS inclinometer casing made by BASF Resin grade in case of outer diameter Φ70, wall thickness 4.0 mm could endure maximum load up to 640kgf. • Top edge of ABS inclinometer casing damaged to the axial direction is not common but we may guess below ; • As strain at break at normal temperature is 11 %, ABS resin itself has no influence on casing damage. • However it would sometimes results from unusual stress concentration at rib area and weak molecular union during work under high temperature and low pressure. The basic chemical resin of ABS inclinometer casing are robust since high modulus of BASF grade made of balanced properties having high strength, modulus, and durability. Therefore the end user has to consider optimized installation way before use.