Forced response of shrouded blades with a coupled static/dynamic approach

A coupled static-dynamic method is proposed and applied to bladed disks with shrouds, in order to calculate the nonlinear forced response in presence of friction damping in the frequency domain. The novel approach allows to improve the already existing methods, which require a preliminary static analysi

A review on analysis of ferrocement panels

Ferrocement is a highly versatile form of reinforced concrete made up of wire mesh, sand, water, and cement, which possesses unique qualities of strength and serviceability. It displays a series of advantages compared to reinforced concrete. Now a days ferrocement is widely used in engineering application due to high performance regards to the resistance to extension, resistance to impact, ductility. Numerous studies were conducted to understand the behaviour of ferrocement panels. This paper presents the review of studies conducted about the behaviour of ferrocement panel under static, dynamic, cyclic loading. Keywords- Ferrocement, cyclic loading, flexural behaviour, precast ferrocement wall, dynamic analysis, static analysi

Combining Forward and Backward Abstract Interpretation of Horn Clauses

Alternation of forward and backward analyses is a standard technique in abstract interpretation of programs, which is in particular useful when we wish to prove unreachability of some undesired program states. The current state-of-the-art technique for combining forward (bottom-up, in logic programming terms) and backward (top-down) abstract interpretation of Horn clauses is query-answer transformation. It transforms a system of Horn clauses, such that standard forward analysis can propagate constraints both forward, and backward from a goal. Query-answer transformation is effective, but has issues that we wish to address. For that, we introduce a new backward collecting semantics, which is suitable for alternating forward and backward abstract interpretation of Horn clauses. We show how the alternation can be used to prove unreachability of the goal and how every subsequent run of an analysis yields a refined model of the system. Experimentally, we observe that combining forward and backward analyses is important for analysing systems that encode questions about reachability in C programs. In particular, the combination that follows our new semantics improves the precision of our own abstract interpreter, including when compared to a forward analysis of a query-answer-transformed system.Comment: Francesco Ranzato. 24th International Static Analysis Symposium (SAS), Aug 2017, New York City, United States. Springer, Static Analysi

Comparison of 2-D and 3-D Dynamic Analysis of Effective Stress of Earth Dams

Presented in this paper is a comparison between the results of 2-D and 3-D dynamic effective stress analyses of a hypothetical earth dam and two real tailing dams. The study is based on a method of rigorous nonlinear dynamic analysis by taking account the interaction of the fluid and soil phase of the material

Seismic Analysis as a Tool in the Design of Two Earth Dams

Two dynamic analysis studies of embankment dams are described. One dam is 43m high on alluvium, the other is 140m high on a rock foundation in a highly seismic area. The main emphasis is on the practical nature of the analytical methods and their value as design tools. The earthquake design features of both projects are described and the closing paragraphs attempt to draw attention to the main points to be considered when running an earthquake analysis of earth dams

Unconstrained Dynamic Simulation on Offshore Dual Derrick

With the increase in demand for oil and oil products, the petroleum industry is faced with the requirement for more complex tools to increase production at lower prices. The complexity of drilling tools is manifested in the complex geometry, fabrication, assembly, deformations, stresses and loads acting on them. This study introduces a dual derrick simulation procedure in a marine environment which provides a step towards a better understanding by giving a simulation close to the real state. The derrick was considered in equilibrium, and then the derrick vibration was simulated using field data in order to obtain stress distribution. This implies that the derrick can move freely and cause deformations in all directions without constraints. In this paper, the finite element method was employed to simulate the derrick in a static state and in motion, and then the obtained stress distribution was compared for both cases. A literature review on the analysis of environment working conditions is provided. The results showed that the vibration of the platform increased the stress considerably. The maximum combined stress increased by 27 %, while the maximum bending stress increased by 40 % and reached considerably higher values in the beams connected to the top of the derrick

Laterite as a base and subbase material for flexible pavement – a review

Rapid economic growth is leading to ubiquitous expansion in highway projects around the world. Utilization of natural aggregate resources for the construction of flexible pavement has led to uncontrollable quarrying in the state of Kerala. The recent landslides in Kerala which took the lives of many people is the aftermath of extensive quarrying activities. Utilization of treated native soil in the structural layers (Subbase and base) of flexible pavement can widely avert the danger associated with ecological imbalance due to quarrying. The main objective of this review article is to enlighten the researchers and practicing engineers about the key advances developed in the last 10 years for utilizing native laterite soil in the base and subbase layers of flexible pavement. On the basis of various researches, laterite soil treated with lime, cement and other additives showed considerable enhancement in the compaction characteristics, unconfined compressive strength (UCS) and California Bearing Ratio (CBR). As stipulated by MORTH (Ministry of Road Transport and Highways), for a layer to be suitable as a subbase material in flexible pavement, minimum CBR value must be 30%. From the extensive review, it was found that the treated laterite soil satisfied the MORTH criteria for use as a subbase layer in flexible pavement. Keywords- Ferrocement, cyclic loading, flexural behavior, precast ferrocement wall, dynamic analysis, static analysi

Simultaneous Firing of Production Rules on Tree Structured Machines

This paper describes a method to realize the simultaneous firing of production rules on tree c structured machines. We propose a simultaneous firing mechanism consisting of global, communication and global synchronization between subtrees. We also proposes hierarchical decomposition algorithm for production systems which maximizes total throughput by satisfying two requirements, Le. Maximizing parallel executability and minimizing global communication

UPPER LIMB JOINTS AND MOTIONS SAMPLING SYSTEM USING KINECT CAMERA

The needs of research on human posture and its joint-motion relationships are important. Providing a real-time postural measurement tool has attracted the attention of many human postural-related researchers. This study has developed and performed a validation analysis on a new innovative system for sampling and finding the angles of motions of each posture with its related joints using Kinect camera. The validation investigated the static and dynamic accuracy analyses by comparing to a Jamar goniometer and ErgoFellow system. The results showed that Mean Absolute Errors of Kinect in static and dynamic motions are 15.12% and 45.33% respectively. It is concluded that the postural measurement system developed by this study requires further improvements