Advances in Thermographic Stress Analysis and Evaluation of Damage in Composites

2009 ◽  
pp. 428-428-16 ◽  
Author(s):  
D Zhang ◽  
BI Sandor
Keyword(s):  
Stress Analysis ◽  
Analysis And Evaluation

Mechanical Stress Analysis and Evaluation of Hybrid Land Grid Array Attached Large Form Factor Organic Modules

2012 ◽  
Vol 2012 (1) ◽  
pp. 000818-000824
Author(s):  
John Torok ◽  
Shawn Canfield ◽  
Yuet-Ying Yu ◽  
Jiantao Zheng
Keyword(s):  
Form Factor ◽  
Stress Analysis ◽  
Mechanical Stress ◽  
Printed Circuit Board ◽  
Organic Substrate ◽  
Circuit Board ◽  
Bottom Surface ◽  
Mechanical Shock ◽  
Analysis And Evaluation ◽  
Pcb Assembly

Recent industry trends to continue enabling increased server system performance and packaging density has driven the need to implement larger form factor hybrid land grid array (LGA) attached organic modules. In addition, given the need to package multiple modules on a single printed circuit board (PCB) assembly, PCB cross-sections and their corresponding physical properties (e.g., flatness, etc.) as well as module bottom surface metallurgy (BSM) co-planarity require a more detailed understanding of impacts to the compliant as well as the soldered connector interfaces. Lastly, the migration to lead (Pb)-free solders has further complicated the issue given both the change in material properties as well as processing temperatures. In this paper we will discuss the mechanical stress analysis and evaluation tests assessment of a recently developed 50 mm square organic processor module, hybrid LGA attached to a multiple site PCB. The analysis presented will highlight the methodology to identify both connector soldered stress and predicted contact load variation across the module's mated interface. Key parameters discuss will include the PCB flatness, Organic substrate BSM co-planarity (both predicted and measured) and the Hybrid LGA as-soldered contact co-planarity. Corroborating predicted analytical results, we will discuss various evaluation tests performed to validate the design's integrity. Key tests include, pressure sensitive film (PSF) studies and environment stress exposures, including thermal shock, mechanical shock and vibration and seismic exposure. Post test electrical integrity and test sample construction analysis, including 3D x-ray and mechanical cross-section, will also be described. The analysis process and testing described will provide a method to evaluate more challenging hybrid LGA applications as both module sizes and/or number applied per PCB assembly increase and Pb-free assembly is introduced in future applications.

The Stress Analysis of the Industrial Fiber-Reinforced Concrete Slab on Elastic Subgrade Loaded by the Operational Loading

2014 ◽  
Vol 617 ◽  
pp. 46-49 ◽  
Author(s):  
Ján Kortiš
Keyword(s):  
Numerical Simulation ◽  
Stress Analysis ◽  
Concrete Slab ◽  
Fiber Reinforced Concrete ◽  
Heavy Vehicles ◽  
Reinforced Concrete Slab ◽  
Analysis And Evaluation ◽  
Different Characteristics ◽  
Different Thickness ◽  
Factory Building

Floors which are used for factory building are usually located in an environment where is expected to be used heavy vehicles and also heavy supplies stored on the floor. What means that these structures have to be designed to withstand the action of the forces. For that reason it is useful to do a numerical simulation followed by stress analysis and evaluation of results. The parametric study was done to compare the influence of different thickness and different characteristics of the subgrade on the values of stress in a concrete slab. It was loaded by forklifts and structures used for storage of material and products.

Voice stress analysis and evaluation

2001 ◽  
Author(s):  
Darren M. Haddad ◽  
Roy J. Ratley
Keyword(s):  
Stress Analysis ◽  
Analysis And Evaluation ◽  
Voice Stress
Sign in / Sign up

Export Citation Format

Share Document