Sustainable slow maintained pile load test

Slow maintained load test is widely used by contractors in Malaysia to ensure the driven pile could accommodate the design load of the structure. Slow maintained load test is a test to determine load-settlement curve and pile capacity for a period of time using conventional load test. Conventional static pile load test equipment is large in size thus making it heavier and takes a long time to install. In addition, it consumes a lot of space which causes congestion at construction sites. Therefore, the objective of this thesis is to conduct a conventional load test by replacing the pile kentledge load with anchorage and reaction pile. Preparations of ten designs comprising six commercial designs were reviewed. In addition, four proposed designs were suggested for the setup. Final design was produced based on its safety factors and criteria referred via literature review. The test frame consists of reaction frame with four reaction helical pile with two helixes per reaction pile. The deformation shapes, safety factor, stress, and strain of the design and finite element of the model has been analysed with the use of SolidWorks and Plaxis 3D software. SolidWorks software emphasizes on the model load-deflection relationship while Plaxis 3D ensures a correlation of reaction between pile uplift force and soil. Then, the model was tested on site to determine the relationship between physical load-deflection and pile-soil uplift force. The results of uplift force and displacement for numerical and physical test were nearly identical which increment of load-displacement graph pattern. The higher the uplift force, the higher the displacement obtained. In conclusion, the result obtained and the design may be considered as a guideline for future application of sustainable slow maintained pile load test

Load Cell Test Pada Fondasi Jembatan Suramadu

At present, Suramadu Bridge is the longest bridge in Indonesia, having 5.438 m length. The uniqueness of this bridge is the three parts which divide the bridge, those are approaching bridge, main bridge, and causeway. This bridge also provides a special lane for motorists outside of the bridge. For the feasibility test of these bridges, it requires a test to the load to verify the real carrying capacity which is able to be borne by the bridge. Article present a case of foundation which has a large dimension and carrying capacity, by the testing method that is done very limitedly; such as Statnamic and Load Cell Test, or Osterberg Cell Test. Based on the result of the Load Cell test - first phase, a decision to implement Load Test second phase is made. Because it is proposed to use a grouting on the tip of foundation, Load Cell second phase is implemented before and after the grouting. From the results of Load Cell Test second phase, it seems that the implementation of Grouting does not significantly increase the carrying capacity, but give a large contribution on the carrying capacity of friction

Large signal 2nd harmonic on wafer MESFET characterization

An automatic test set which performs a real time harmonic load-pull characterization is proposed. An active load technique is used in order to set the load at the test frequency and its harmonics and a complete set of device parameters useful for power amplifier design purposes can be measured versus the harmonic loads. The calibration procedure, based on substrate and coaxial standards, has been mainly developed for on wafer measurement in order to set the reference planes directly on the DU

Material Fatigue Testing System

A system for cyclicly applying a varying load to a material under test is described. It includes a load sensor which senses the magnitude of load being applied to a material, and, upon sensing a selected magnitude of loading, causes the load to be maintained for a predetermined time and then cause the system to resume cyclical loading

Optimal under voltage load shedding based on stability index by using artificial neural network

Power system is exceptionally sensitive at the generation and consumer side. Inconsistent power requirement under general power production environment may cause power system to approach breakdown or power outages. Load shedding is deliberated as the final choice from the numerous techniques which have been achieved to prevent voltage breakdown. Various studies have been led on this part of the issue. Still, there are possibilities for other ways through optimization of the load shedding. Consequently, the primary reason for this work is to come up with an optimal undervoltage load shedding strategy. Voltage stability is one of the significant worries in functional and preparation of present-day power system. Nevertheless, to obtain the lowest amount to be shed in order to avoid voltage instability, optimization is required. An algorithm was developed to shed the optimal load by considering the load priority whereby the load with least priority will be shed first. The algorithm is working in one step to shed the load. The developed algorithm was tested on IEEE 33-Bus and IEEE 69-Bus radial distribution systems. The results show the equal accuracy of the application of the developed algorithm. In this project, a powerful technique is exhibited for evaluating the optimal amount of load to be shed in a radial distribution system by using artificial neural network. The results of these test cases confirm that 6.57% of bus voltage is increased at the weakest bus in the IEEE 33-Bus system and 10.23% of bus voltage is increased at the weakest bus in the IEEE 69-Bus system. This optimal load shedding algorithm does not over shed or under shed the load. Other achievement includes reduction in load shedding steps. For each test case, the complete load shedding was achieved in 1 step only and the amount of load shed is suitable in each test case respectively. In this project, 29.4% of load is curtailed to stabilize the system which is less compared to other works where about 30% of load is shed to stabilize the system

A Comprehensive Mixed-Mode Time-Domain Load- and Source-Pull Measurement System

We present a novel test set devised for nonlinear balanced device characterization using load-pull techniques. The system is capable of measuring the voltage and current waveforms at the calibration reference planes while independently tuning the device under test (DUT) source and load differential- and common-mode terminations. The test set is designed to address present and future large-signal multiport measurement needs, easing the characterization task while developing new multiport active device

Design and commission of an experimental test rig to apply a full-scale pressure load on composite sandwich panels representative of aircraft secondary structure

This paper describes the design of a test rig, which is used to apply a representative pressure load to a full-scale composite sandwich secondary aircraft structure. A generic panel was designed with features to represent those in the composite sandwich secondary aircraft structure. To provide full-field strain data from the panels, the test rig was designed for use with optical measurement techniques such as thermoelastic stress analysis (TSA) and digital image correlation (DIC). TSA requires a cyclic load to be applied to a structure for the measurement of the strain state; therefore, the test rig has been designed to be mounted on a standard servo-hydraulic test machine. As both TSA and DIC require an uninterrupted view of the surface of the test panel, an important consideration in the design is facilitating the optical access for the two techniques. To aid the test rig design a finite element (FE) model was produced. The model provides information on the deflections that must be accommodated by the test rig, and ensures that the stress and strain levels developed in the panel when loaded in the test rig would be sufficient for measurement using TSA and DIC. Finally, initial tests using the test rig have shown it to be capable of achieving the required pressure and maintaining a cyclic load. It was also demonstrated that both TSA and DIC data can be collected from the panels under load, which are used to validate the stress and deflection derived from the FE model

Recent Advances in Real-Time Load-Pull Systems

In this paper, some of the latest advances in real-time load-pull technologies will be described. A recently introduced ultralow-loss directional coupler, which has been designed and realized by the authors, provides a number of advantages when used in load-pull test sets. This device has been called the load-pull head. The new ultralow-loss load-pull head can transform any passive precalibrated load-pull system into an easily calibrated and accurate real-time load-pull test set, without losing highreflection- coefficient capabilities. Moreover, if used to realize an active loop, the load-pull head reduces the risks of oscillations and the amount of the loop amplifier output power. As an example application, measurements with a passive real-time load-pull setup of a 30-W laterally diffused MOS (LDMOS) transistor are presented. Furthermore, some advice to bypass the remaining unavoidable losses due to probes and cables is given.We will show, with measurements and with very simple calculations, that the combined use of load-pull heads, a passive tuner, and an active loop not only boosts the available ΓL but also decreases the loop amplifier output power, with a sensible reduction in the overall cost of the syste

Human sensitivity to gearshift loads

This paper describes an investigation of the ability of humans to distinguish different levels of gearlever load. A test rig with a forward-backward moving gearshift lever was constructed using the typical interior dimensions of European B segment automobiles. The rig used a system of weights and pulleys to provide a load which could be varied in steps of 1%. Four reference loads were chosen which were considered representative of automotive gearshift operation: 0.5, 1.0, 2.0 and 5.0 kg. Twenty subjects took part in the study. Using a variation on the psychophysical method of limits, the subjects were asked to respond whether a test load was heavier or lighter than a reference load. The Weber Fraction was found to decrease monotonically from a value of 0.036 for the 0.5 kg reference load to a value of 0.029 at the 5.0 kg reference load. The average value across all reference loads was 0.032. Measurements of the gearshift force made by means of a knob containing a load cell suggested that the variation in the measured Weber Fraction might be attributable to the time behaviour of the force exchanged between the human subject and the control surface