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In order to design more efficient and reliable structures, axial load tests are performed on foundation piles. Traditionally, static tests with an average duration of approximately twenty-four hours have been performed on test piles to obtain their axial capacity. These static tests require multiple piles used as anchors in addition to the test pile. Static tests are both expensive and time consuming. An alternative to static testing is dynamic testing which requires sophisticated interpretation, can damage the pile and may not produce accurate results. There is a relatively new testing method called the Statnamic Testing Method which tests foundation piles at a very fast rate, but still slower than with dynamic tests. As the rate at which load is applied to a test pile increases, the axial capacity also increases, particularly in clay. Research suggests that shear strength of soil typically increases 10% per log cycle increase in strain rate. Strain rate effects can vary widely and may be influenced by many factors including plasticity index, structure, ageing, overconsolidation ratio, temperature, etc. Statnamic testing was performed for this work. Nine static tests were performed on six different piles identical to the Statnamic test pile and driven through the same soil profile. The static tests had times to failure ranging from ten seconds to eighteen hours. Failure load increased by 13.7% per log cycle increase in velocity. Statnamic tests need more careful analysis when performed in clay to avoid over predicting pile capacity. A factor of 0.55 should be applied to Statnamic capacity to predict static capacity.

In this work the susceptibility of Fe-10Cr-4Al steel to liquid metal embitterment (LME)in low oxygen environment was investigated. slow strain rate testing (SSRT) wereconducted on 10-4 FeCrAl steel in a stagnant lead from 340-480◦C, lead-bismutheutectic (LBE) from 140-450◦C and lead-bismuth mixture at 375◦C with increasingbismuth content from 0.1wt%-40wt%. The results showed that in the stagnant leadenvironment the FeCrAl steel showed no sign of LME with all samples being subjectedto around 25% strain before final break. In LBE the samples were affected by LMEespecially at 350-400◦C. The total elongation to failure reduced in LBE from 25%to 13.1% and a ductility trough from 190-400◦C was observed. In the lead-bismuthmixture there was a reduction in ductility at 5wt% going from 25% to 20% totalelongation, at 15wt% going from 20% to 16% total elongation and at 30wt% going from16% to 13% total elongation. / I det här arbetet har stålet Fe-10Cr-4Al känslighet till liquidmetal embrittlemnt(LME)i låga syre miljöer av flytande bly, mellan 340-480 °C, och Bly/Vismut eutektisk (LBE),mellan 140-450 °C, undersökts. En stegvis ökning av Vismut halten i flytande blygenfördes också från 0.1 wt% Bi till 40 wt% Bi med en fast temperatur på 375 °C.Resultaten från dessa experiment visade att i ren bly miljö så visade stålet Fe-10Cr-4Al inga tecken på LME, alla prover gick till brott runt 25% strain. I LBE blev ståletsvårt på verkat av LME, framför allt inom temperaturer intervallet 350-400 °C. Dentotala förlängningen av proverna blev här reducerat från 25% ner till 13.1% och en klarduktilitets tråg mellan 190-400 °C kunde observeras. I experimenten med gradvisökande Vismut halt observerades markanta nedgångar i stålets duktilitet vid 5 wt%Bi då den droppar från 25% till 20% förlängning, nästa dropp observerades vid 15 wt%Bi, 20%-16% och vid 30 wt% Bi med ett reduktion från 16% till 13%.

No / The formation of tribo-layers during machining is very common phenomena, especially when machining `free machining¿ steels. Several kinds of tribo-layers formed in metal cutting processes have been reported, layers of inclusions from the workpiece, oxide layers due to chemical reaction, plastic deformation layers, material transfer layers (MTLs) or built-up layers (BULs). A new tool¿chip contact model is proposed to explain the tribo-layer phenomena, which considers the nature of the shear strain rate distribution in the secondary deformation zone. A shear strain rate distribution in this zone having a shape similar to that found in the preliminary zone is proposed. A cutting interface (CI) is defined and this interface is at different location to the material boundary of tool and chip (MBTC). This difference is a key factor in the formation of the tribo-layer in the secondary deformation zone. This model can be used in improving tool wear prediction and the estimation of tool life.

<p>In an AP-HTPB propellant microstructure, the local strain rate depends on the AP crystal size and the material, while the local temperature rate depends on the impact velocity, AP crystal size, and the material.  Larger AP crystals lead to higher local strain rates and higher local temperature rates, which means hot spots are more likely to occur in AP-HTPB propellants with more large AP crystals.</p>

Experiments were conducted on ASTM A572 50 and A992 steel over a range of intermediate strain rates in order to determine material strength properties of structural members subjected to dynamic loadings. The yield and ultimate tensile stress (UTS) of the steels were determined at increasing strain rates using a hydraulic apparatus and compared to static values obtained from ASTM E8 standardized tensile experiments. Results revealed that A572-50 steel exhibited an increase in yield stress of up to 35% and UTS of up to 20% as strain rate increased from 0.002 to 2.0 s-1. A992 steel demonstrated a similar increase in yield stress of up to 45% and UTS of up to 20%. Ratios of dynamic-to-static strengths were used to develop dynamic increase factor curves spanning the range of strain rates studied. These curves provide designers with material property values required for accurate and economical design of protective structures.

The object of this study was to investigate the micro-structural response of DP 600 subjected to high strain rate, ballistic impact tests. The ballistic tests were conducted using normal impact of a hardened steel penetrator into a 2 mm thick sheet of DP 600. The average strain rates produced from this test method are on the order of 10^5 s-1. Multiple methods were used to investigate the micro-structure before and after high strain rate deformation including optical microscopy, electron microscopy, and X-ray diffraction. A large variation in material response was observed between tests conducted at 0.8 x 10^5 and 2.5 x 10^5 s-1.

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