The strength of ball joints in space trusses – Part III

2021 ◽  
pp. 123-132
Author(s):  
T. Tanaka ◽  
H. Kanatani ◽  
M. Tabuchi
Keyword(s):  
Ball Joints ◽  
Space Trusses

FUNDAMENTAL STUDY ON THE STRENGTH OF BALL JOINTS IN SPACE TRUSSES

1993 ◽  
Vol 452 (0) ◽  
pp. 129-138
Author(s):  
Tsuyoshi TANAKA ◽  
Hiroshi KANATANI ◽  
Mototsugu TABUCHI
Keyword(s):  
Fundamental Study ◽  
Ball Joints ◽  
Space Trusses

scholarly journals STRENGTH OF BALL JOINTS WITH DIAPHRAGM IN SPACE TRUSSES

1995 ◽  
Vol 60 (468) ◽  
pp. 137-146
Author(s):  
Tsuyoshi TANAKA ◽  
Hiroshi KANATANI ◽  
Mototsugu TABUCHI
Keyword(s):  
Ball Joints ◽  
Space Trusses

AISI 1141

Alloy Digest ◽  
1983 ◽  
Vol 32 (3) ◽  
Keyword(s):  
Carbon Steel ◽  
Transverse Direction ◽  
Longitudinal Direction ◽  
Heat Treating ◽  
Automatic Machine ◽  
Steel Mills ◽  
Light Duty ◽  
High Production ◽  
Ball Joints ◽  
Machining Characteristics

Abstract AISI 1141 is a resulfurized carbon steel containing nominally 1.50% manganese and 0.08-0.13% sulfur to give it free-machining characteristics. It has relatively low hardenability. Its ductility and toughness are fairly good in the longitudinal direction but tend to be low in the transverse direction. It is highly recommended for high-production automatic-machine products. Among its many uses are screws, bolts, ball joints, spindles and light-duty gears. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: CS-93. Producer or source: Carbon steel mills.

Failure Analysis of Flip-Chip Interconnections Through Acoustic Microscopy

1996 ◽  
Author(s):  
O. Diaz de Leon ◽  
M. Nassirian ◽  
C. Todd ◽  
R. Chowdhury
Keyword(s):  
Failure Analysis ◽  
Large Scale ◽  
Flip Chip ◽  
Ultrasonic Waves ◽  
Acoustic Microscopy ◽  
Acoustic Microscope ◽  
Chip Technology ◽  
Ball Joints ◽  
Non Destructive ◽  
Scanning Acoustic Microscope

Abstract Integration of circuits on semiconductor devices with resulting increase in pin counts is driving the need for improvements in packaging for functionality and reliability. One solution to this demand is the Flip- Chip concept in Ultra Large Scale Integration (ULSI) applications [1]. The flip-chip technology is based on the direct attach principle of die to substrate interconnection.. The absence of bondwires clearly enables packages to become more slim and compact, and also provides higher pin counts and higher-speeds [2]. However, due to its construction, with inherent hidden structures the Flip-Chip technology presents a challenge for non-destructive Failure Analysis (F/A). The scanning acoustic microscope (SAM) has recently emerged as a valuable evaluation tool for this purpose [3]. C-mode scanning acoustic microscope (C-SAM), has the ability to demonstrate non-destructive package analysis while imaging the internal features of this package. Ultrasonic waves are very sensitive, particularly when they encounter density variations at surfaces, e.g. variations such as voids or delaminations similar to air gaps. These two anomalies are common to flip-chips. The primary issue with this package technology is the non-uniformity of the die attach through solder ball joints and epoxy underfill. The ball joints also present defects as open contacts, voids or cracks. In our acoustic microscopy study packages with known defects are considered. It includes C-SCAN analysis giving top views at a particular package interface and a B-SCAN analysis that provides cross-sectional views at a desired point of interest. The cross-section analysis capability gives confidence to the failure analyst in obtaining information from a failing area without physically sectioning the sample and destroying its electrical integrity. Our results presented here prove that appropriate selection of acoustic scanning modes and frequency parameters leads to good reliable correlation between the physical defects in the devices and the information given by the acoustic microscope.

No more rattling: biomechanical evaluation of a hexapod ring fixator free of play

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Markus Greinwald ◽  
Emily K. Bliven ◽  
Alex Trompeter ◽  
Peter Augat
Keyword(s):  
Mechanical Performance ◽  
Steel Frame ◽  
Ball Joint ◽  
Universal Joint ◽  
Ring Fixator ◽  
Low Weight ◽  
Biomechanical Evaluation ◽  
Axial Fracture ◽  
Ball Joints ◽  
Universal Joints

Abstract Hexapod-ring-fixators have a characteristic rattling sound during load changes due to play in the hexapod struts. This play is perceived as unpleasant by patients and can lead to frame instability. Using slotted-ball-instead of universal-joints for the ring-strut connection could potentially resolve this problem. The purpose of the study was to clarify if the use of slotted-ball-joints reduces play and also fracture gap movement. A hexapod-fixator with slotted-ball-joints and aluminum struts (Ball-Al) was compared to universal-joint-fixators with either aluminum (Uni Al) or steel struts (Uni Steel). Six fixator frames each were loaded in tension, compression, torsion, bending and shear and mechanical performance was analyzed in terms of movement, stiffness and play. The slotted-ball-joint fixator was the only system without measurable axial play (<0.01 mm) compared to Uni-Al (1.2 ± 0.1) mm and Uni-Steel (0.6 ± 0.2) mm (p≤0.001). In both shear directions the Uni-Al had the largest play (p≤0.014). The resulting axial fracture gap movements were similar for the two aluminum frames and up to 25% smaller for the steel frame, mainly due to the highest stiffness found for the Uni-Steel in all loading scenarios (p≤0.036). However, the Uni-Steel construct was also up to 29% (450 g) heavier and had fewer usable mounting holes. In conclusion, the slotted-ball-joints of the Ball-Al fixator reduced play and minimized shear movement in the fracture while maintaining low weight of the construct. The heavier and stiffer Uni-Steel fixator compensates for existing play with a higher overall stiffness.

A New Reinforcement Measure Suited for Space Truss with No-Fire Operation

2014 ◽  
Vol 919-921 ◽  
pp. 401-405
Author(s):  
Zuo Yun Mei ◽  
Chuan Qing Liu ◽  
Xing Mi ◽  
Ping Wu
Keyword(s):  
Element Model ◽  
High Yield ◽  
Nonlinear Analyses ◽  
High Yield Strength ◽  
Shell Elements ◽  
Gas Stations ◽  
Space Truss ◽  
Reinforcement Measure ◽  
Space Trusses ◽  
Elastic Stage

A new reinforcement measure with no-fire operation is presented, which is very suitable for space trusses which are located in gas stations. A finite element model (FEM) is presented with shell elements and multipoint constraint elements. With this FEM, nonlinear analyses are carried out. Analytical results show that integral failure of reinforced pipe is caused by yielding of original pipe inside. So it is not necessary to reinforce original pipe using steel pipe bonded outside with high yield strength. With the increase of length of bonded pipe outside, loading according to elastic stage and ultimate bearing loading increase, it is clear that the length of bonded pipe outside is an important factor which influences the bearing capacity.

The Seismic Damage Investigation and Phenomenon Analysis of Space Grid Structures in Lushan Ms 7.0 Earthquake

2014 ◽  
Vol 501-504 ◽  
pp. 1535-1541 ◽  
Author(s):  
Jue Hui Xing ◽  
Ming Lu ◽  
Hai Wang Li ◽  
Ya Min Zhao ◽  
Yan Yu
Keyword(s):  
Seismic Design ◽  
Shell Structure ◽  
Historical Earthquakes ◽  
Seismic Damage ◽  
Grid Structure ◽  
Paper Briefly ◽  
Space Grid ◽  
Reticulated Shell Structure ◽  
Ball Joints ◽  
Damage Investigation

People remained optimistic about the safety of the space grid structures, because the seismic damages of space grid structures were quite rare and rather light. However, two space grid structures got damaged in 2013 Lushan Ms 7.0 earthquake. The two structures are the double-layer reticulated shell structure and flatbed grid structure, namely Lushan Gymnasium and Lushan Middle School Gymnasium respectively. This paper briefly reviews the seismic damage phenomena of grid structures in historical earthquakes, and then focuses on the two damaged space grid structures in Lushan earthquake. The reason why the two space grid structures got damaged are derived from the force state analysis of the rods, ball joints and bearings. Finally, we come up with the effective advice for the seismic design and construction of the space grid structure.

The beam-like behavior of space trusses

AIAA Journal ◽  
1984 ◽  
Vol 22 (2) ◽  
pp. 273-280 ◽  
Author(s):  
John D. Renton
Keyword(s):  
Space Trusses
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