Strain Softening Research Articles

Do soft soil layers reduce the seismic kinematic distress of onshore high-pressure gas pipelines?

AbstractOnshore high - pressure gas pipelines constitute critical infrastructure that usually cross seismic - prone regions and are vulnerable to Permanent Ground Deformations (PGDs) due to active seismic faults. In design, it may not be feasible to avoid fault rupture areas due to various technical, economical and topographic reasons. Moreover, the presence of soil layers affects the PGDs resulting from a tectonic fault, which in turn may alter the seismic demand on the pipeline. The current study investigates numerically the impact of soft soil layers on the seismic kinematic distress of onshore gas pipelines. For this purpose, a decoupled numerical modeling approach is adopted, consisting of two separate finite - element models for the simulation of soil response and pipeline distress, respectively. Soil non - linearities are taken into account utilizing the Mohr - Coulomb constitutive model with isotropic strain softening. An extensive parametric analysis is performed considering different faulting mechanisms and fault dip angles, as well as soil geometry and mechanical properties. Consequently, the maximum absolute values of both tensile and compressive pipeline strains are correlated with the seismic intensity level (i.e., in terms of bedrock offset which is associated with earthquake magnitude via simple relationships). The paper concludes with a set of design charts and tables for the preliminary seismic design of onshore high - pressure gas pipelines. These charts and tables predict with reasonable accuracy pipeline deformations, in terms of strains, for different magnitude, fault type, dip angle, sand type, and varying overlying soil layer thickness.

In-plane compressive behavior of short cross-laminated bamboo and timber

This study investigated the post-yield behavior of 5-layer cross-laminated bamboo and timber (CLBT) short wall specimens under in-plane compressive loading, and cross-laminated timber (CLT) specimens were used as the control. Compared to CLT, the replacement of the outermost spruce-pine-fir layers in CLBT with bamboo scrimber layers led to a 90% increase in compressive strength and a 20% increase in compressive modulus in the major strength direction. A quantitative evaluation employing absolute and relative error indicators demonstrated that the Richard-Abbott model adequately predicted the tested stress–strain relationships. In contrast to CLT, CLBT exhibited a more extended strain hardening stage after yielding and a shorter strain softening stage after the maximum point, particularly in the major strength direction. The ductility and toughness indices of CLBT, calculated based on the yield and failure points, were higher than those of CLT in the major and minor strength directions. The energy absorption provided a better representation of toughness characteristics for CLBT and CLT compared to the toughness index. This study provides a technical database and guidelines for the application of mass hybrid bamboo and wood products in the construction industry.

Tectono-metamorphic evolution and strain partitioning along the Mugesse mega shear zone, Ubendian Belt (Northern Malawi)

In this contribution we focus on a portion of the Mugesse mega shear zone (MGSZ) in the Ubendian Belt, for which details on kinematics and strain partitioning remains poorly documented. We present a field-based structural work, a petrological and thermobarometrical study of mylonites and LA-ICP-MS in-situ U-Pb dating on monazite and zircon. The detailed field mapping highlights that the whole study area shows the same sinistral strain pattern with deformation being partitioned within S-C and C-C’ structures. Syn-kinematic metamorphic mineral assemblages indicate that the MGSZ mylonites recorded a clockwise P-T evolution with peak temperature conditions at upper amphibolite metamorphic facies of 11–15 kbar and 760–790 °C. Retrogression and cooling reached P-T conditions of 1–7 kbar and 330–480 °C. LA-ICP-MS in-situ U-Pb monazite dating suggests that the main activity of the MGSZ was Pan-African, at ca. 547 ± 5 and 545 ± 4 Ma. Zircon dates at 1985 ± 44 Ma and 1127 ± 29–988 ± 10 Ma are interpreted as inherited ages of potentially detrital origin related to the Ubendian and Irumide orogeny, respectively. A 1146 ± 14 Ma date obtained on zircons from the Lwakwa mylonitic orthogneiss is interpreted as the crystallisation age of the granitic protolith that intruded the Paleoproterozoic basement. Strain partitioning and strain softening during the growth of the MGSZ was strongly controlled by feedback relationships between deformation and retrograde metamorphism enhanced by fluid ingress and recrystallisation.

Role of void nucleation at primary-γ'/γ interface on strain softening of nickel base superalloy 720Li

High-temperature tensile deformation behavior of polycrystalline nickel based superalloy 720Li used for manufacturing aero engine disks was studied by conducting uniaxial tensile tests in the temperature range of 25–800 °C and subsequent transmission and scanning electron microscopic examinations to decipher strain hardening/softening behavior. The alloy is strengthened by different sizes of γ'-precipitates named as primary, secondary, and tertiary-γ'. The sizes of primary γ' is in the range of 0.5–3 µm and most of them are incoherent with γ-matrix as confirmed by the TEM study. From engineering stress-strain curves, it was observed that specimens tested in the temperature range 25–650 °C exhibited a significant amount of strain hardening, whereas specimens tested at 720 and 800 °C softened after the onset of plastic yielding. From extensive SEM examinations, it is concluded that void nucleation at primary-γ'/γ interface at 720 and 800 °C was the main reason for strain softening after the onset of plastic yielding. Nucleation of voids at primary-γ'/γ interface is ascribed to (i) γ' size, which loses coherency with the matrix after reaching a critical value (rcrit); and (ii) difference in Schmid factor between γ' precipitate and γ matrix, which varies with test temperature. From the misfit data, the rcrit values were calculated at 25 and 800 °C and are found to be in the range of 1250–1500 nm and 150–200 nm, respectively. From the electron backscatter diffraction (EBSD) analysis, it is confirmed that at 720 and 800 °C when the difference in Schmid factors between γ' precipitate and γ-matrix is ≥ 0.1, the probability of formation of the void is high.

Relaxed Incremental Formulations for Damage at Finite Strains Including Strain Softening

AbstractRelaxation is a promosing technique to overcome mesh‐dependency in computational damage mechanics originating from the non‐convexity of an underlying incremental variational formulation. This technique does not require an internal length scale parameter. However, in case of damage formulations, for many years the decrease of stresses with an increase of strains, referred to as strain‐softening, could not be modeled in the relaxed regime. This contribution discusses several possibilities of relaxation that lead to suitable models for stress‐ and strain‐softening.

Soil particle size-dependent constitutive modeling of frozen soil under impact loading

In this study, the soil particle size dependence of the impact dynamic mechanical properties of frozen soil was investigated using a split Hopkinson pressure bar, and the meso-deformation mechanism of frozen soil was analyzed via electron microscopy. Under impact loading, the dynamic stress-strain curves of frozen soil showed strain hardening, strain softening, strain rate-temperature sensitivity, and soil particle size dependence, and the soil particle size dependence of frozen soil was considered to be significantly influenced by non-uniform meso-deformation, which primarily appeared in the form of microcracks surrounding the coarse particles. A constitutive model comprising a multiplicative hardening law was proposed, and soil particle size dependence was introduced through the equivalent strain gradient of the soil cell element. The impact compression process of frozen soil was simulated in ABAQUS/Explicit using the proposed model, and the mechanism of frozen soil deformation was summarized by the finite element analysis: the stress concentration around coarse particles induces the initiation of microcracks, the propagation of microcracks forms a crack network, eventually leading to the softening behavior of frozen soil.

FRP bar-reinforced ultra-high-performance concrete plates with a grouting sleeve connection: Development and flexural behavior

Fiber reinforced polymer (FRP) bars have been proposed for use in ultra-high performance concrete (UHPC) as the reinforcement to mitigate/avoid the post-peak strain softening of UHPC under tension and to reduce the fiber dosage used in UHPC. The so-formed FRP-reinforced UHPC plates could be adopted for both structural strengthening and constructing novel structural elements. In this paper, a novel connection based on FRP bars and steel grouting sleeves has been developed for prefabrication construction of FRP bar-reinforced UHPC structures. Flexural tests were conducted to gain understandings of the effects of the connection mode (the staggered connection and the horse tooth connection) and reinforcing fiber type (polyethylene (PE) fibers and steel fibers) in the UHPC on the flexural behavior of connected FRP bar-reinforced-UHPC composite plates. The test results revealed that the proposed connection system is reliable since the composite plates always failed outside the connection zone, and most of the crack opening displacements at the interface of the connection are smaller than 0.2 mm at ultimate. The connection mode and the fiber type had little influence on the first cracking load and the initial bending stiffness of the FRP bar-reinforced UHPC plates, while the horse tooth connection led to a better ductility of the composites plates than the staggered connection mode. At given tolerable deflection of 1/200 span (about 5 mm), the longitudinal strains developed in the CFRP bars were about 2000 με for all specimens.

Unraveling the deformation behavior of the Fe45Co25Ni10V20 high entropy alloy

Here we report on the tensile deformation behavior of a face-centered cubic (FCC)-structured Fe45Co25Ni10V20 high-entropy alloy at cryogenic temperature (77 K). The alloy displays an impressive 1.1 GPa tensile strength while maintaining an ultrahigh fracture elongation of 82% with a minimum strain hardening rate at a true strain of about 40%. We elucidate such unique mechanical properties, originating from the strain-induced FCC to body-centered cubic (BCC) martensitic transformation, where the high-stress concentrations at grain boundaries or intersection of stacking faults can stimulate phase transition. The martensitic transformation can induce strain softening by consuming the stored deformation energy while contributing to the strain hardening via the transformation itself and further deformation of BCC phases. Such a dynamic balance between softening and hardening enables a relatively uniform plastic flow, resulting in a plastic deformation with a strain range of up to 35% delaying macroscopic necking. The findings provide further insights into the significance of transformation-induced plasticity effects on the cryogenic performance of alloys.

Experimental study of triaxial shear features of concentrated full tailings considering the effect of curing age

The strength evolution law of concentrated full tailings is closely related to the storage construction method, especially the growth law of shear strength with curing age. This study aims to investigate the influence of curing materials on the shear strength of full tailings and reveal the change law of the shear strength of concentrated full tailings with the curing age. Therefore, we carried out a comparative triaxial shear test between pure full tailings and concentrated full tailings with different curing ages. The test results show that concentrated full tailings had a 70.7% higher cohesion and a 10% larger internal friction angle (IFA) than that of pure full tailings at the age of 0 days. Moreover, the concentrated full tailings cured for 3 days had a 170.2% higher cohesion and a 12.1% larger IFA than that cured for 0 days. In addition, the concentrated full tailings cured for 7 days had a 149.4% higher cohesion and a 12.1% larger IFA than that cured for 0 days. The stress-strain curve exhibits that the shear strength of full tailings is significantly influenced by the curing material and curing age. The stress-strain curve gradually moved from strain hardening to strain softening as the curing age increased, and the failure curve had two steps. This indicates that the specimen still has a certain shear capacity despite having a shear zone. The entire specimen instantly fails when the strain exceeds that capacity. The results of this study can be used as scientific bases for the design and construction of the surface storage structures of concentrated full tailings.

Carbon capture and storage potential of biochar-enriched cementitious systems

A promising solution to nullify the net embodied greenhouse gas emissions of civil infrastructure is the use of carbon-negative materials for concrete manufacturing. Carbon-neutral coal ash and agriculture/forestry by-products, such as biochar, exhibit a high carbon dioxide (CO2) uptake potential. The aim of the study is to explore the viability of using biochar as a carbon sink and to develop carbon-neutral concrete with improved performance. Experimental findings suggest that the optimal amount of biochar (1%) slightly improves hydration and mechanical properties, but the combination with mineral additives significantly enhances the performance. Thermogravimetric analysis (TGA) revealed that compared to OPC, the addition of 1% biochar contributes to a 42% increase in CO2 uptake, while the combination of biochar with 10% class C fly ash further increases CO2 capture capacity of the mix by 92%. Under accelerated carbonation conditions, the biochar-enriched mortars exhibit a 20% higher modulus of elasticity indicating an effectively increased stiffness over the reference carbonated OPC. The carbonated biochar mortars also exhibit up to 64% increased toughness indices indicating the material's great resistance to crack coalescence and propagation at the strain softening stage. Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy (SEM-EDS) results validated our prediction that the porous morphology of biochar promoted enhanced CO2 absorption and in-situ mineralization of calcium carbonate, resulting in a denser and stronger cement matrix.

Dynamic mechanical properties of nanoparticle-enhanced aluminum alloys fabricated by arc-directed energy deposition

The nanoparticle-enhanced aluminum alloys fabricated by arc-directed energy deposition (Arc-DED) have gained much attention due to their improved microstructure and enhanced mechanical properties, and are expected to be applied in aerospace, defense, and marine fields. The dynamic properties of nanoparticle-enhanced aluminum alloys are required in the aforementioned fields. In this work, the dynamic behaviors of AA7075 and TiC/AA7075 samples fabricated by Arc-DED in as-built and heat-treated states are investigated by Split-Hopkinson pressure bars tests with the strain rates of 2000–5000 s−1 at room temperature. The results show that adding TiC nanoparticles improve the dynamic properties of aluminum alloys, especially their performance after heat treatment. The improved performance can be attributed to the refined grain and the generated strengthening phase. The metallographic structure shows that the adiabatic shear band (ASB) is first generated with an increase in the strain rate. Then, cracks appear along ASB, leading to the final shear failure. A modified Johnson-Cook constitutive model is proposed based on the strain softening and strain rate softening effects. The results obtained by the proposed model agree with the experimental results. This work is the first to study the dynamic behavior of aluminum alloys fabricated by Arc-DED, which has potential value for applicating aluminum alloys in various industries.

A nonlinear and rate-dependent fracture phase field framework for multiple cracking of polymer

Designing durable polymer-based materials and structures requires understanding how the physical processes and failure mechanisms associated with moisture intrusion and loading rate combine to produce the complex damage modes observed in their applications. While numerous experiments have assisted us in gaining general insight into the above issues, in-situ characterization is still lacking, and rational prediction on the failure procedure of polymer in the moisture–mechanical​ coupling environment remains challenging. Here we present a thermodynamically consistent theoretical framework and its computational implementation to reveal how the dependence of epoxy’s mechanical behavior on rate- and moisture dictates the initiation and evolution of highly localized deformation zones and cracks. A multi-physical hydrothermal-viscoelastic–viscoplastic-damage model is first proposed to fully couple the effects of strain rate, moisture degradation, strain softening, and adiabatic heating of the bulk epoxy in a highly humid environment. The constitutive models are augmented by a phase field that enables spontaneous tracing of the nucleation and growth of cracks under a wide range of strain rates (from 4.60 × 10−5/s to 3.80 × 103/s). The theoretical model is implemented into an efficient computational procedure that is used to calculate illustrative examples to demonstrate the influence of the intimate coupling between the multi-physical phenomena. The results highlight significant mechanisms underlying the coupled damage process, including: heat accumulation along the crack propagation path; identification of the energies associated with moisture-induced toughening; prediction of crack deflection in the presence of moisture absorption; and illustration that a portion of the plastic work plays a dominant role in the nucleation of cracks at a wide scale of strain rates.

Effect of Viscoplasticity on Localization in Saturated Clays and Plastic Silts

A numerical study is presented of the effects of viscoplasticity on localization processes in sensitive, saturated clays and plastic silts. Numerical simulations of laboratory specimens of sensitive, viscoplastic soil subjected to monotonic, undrained, direct simple shear loading were performed using a viscoplastic constitutive model. Parametric analyses evaluated the effects of soil sensitivity, postpeak strain-softening rate, and strain rate dependency, as well as specimen size, mesh discretization, and loading rate. The numerical results showed that the global strain at which a localization forms primarily depends on the strain rate dependency of the soil’s shearing resistance relative to its rate of postpeak strain softening. A regression model is subsequently presented that relates the global strain at the onset of localization to the soil’s strain rate dependency and postpeak strain-softening rate. The results indicate that the inclusion of reasonable levels of viscoplasticity significantly increases the strain that can develop before a localization develops in clays and plastic silts with modest strain-softening rates. The consistency of the numerical results with available laboratory observations is discussed. Implications for practice and future research needs are discussed.

Engineered cementitious composites - a review

Engineered Cementitious Composites (ECC) is also known as bendable concrete, characterized by tight crack width control. As we know the concrete is brittle in nature, expected to fail catastrophically. To minimize the damages caused by the concrete failure in seismic region we go for special detailing to enhance the ductility nature of concrete members, which leads to a complicated design. To overcome this problem a new type of composites are designed called Engineered Cementitious Composites based on a combination of structural engineering and micromechanics. This paper deals with the literature survey on micromechanics design to achieve the pseudo strain hardening behaviour, i.e. to achieve two criteria’s namely i) Strength Criteria ii) Energy criteria. Both Reinforced Concrete and Fiber Reinforced Concrete shows strain softening behaviour after the appearance of the first crack whereas the ECC shows strain hardening behaviour after the appearance of first crack because of the presence of randomly oriented discontinuous fibers. Regarding Strength criteria, Fiber bridging stress plays a major role and for energy criteria, Matrix toughness plays a major part. By tailoring these two parameters, strain hardening behaviour of the composite can be achieved. Apart from these two parameters mixing of fresh ECC is also an important factor to be considered, since uniform dispersion of fibers leads to bridging of the cracks which makes the composite to have a multiple fine cracks before failure instead of having a big single crack.

The influence of strain rate and annealing heat treatments on the corrosion and mechanical properties of WE43 and Zn7Ag biodegradable wires for application in soft tissue reconstructions

This study investigated the influence of annealing heat treatments on the microstructure, corrosion and mechanical behaviour of wires made from the Mg alloy WE43 and the Zn alloy Zn7Ag. The applied strain rate had little influence on the mechanical properties of WE43, whereas decreasing strain rate decreased the strength and increased the ductility of Zn7Ag attributed to creep. The annealing heat treatments had (i) a small influence on the corrosion rate of both WE43 and Zn7Ag wires, (ii) little influence on the mechanical properties of WE43, and (iii) had little influence on the strength of Zn7Ag but tended to decrease ductility and eliminated strain softening. WE43-FA immersed in Zahrina's interstitial fluid (ZIF) for 12 days had a yield strength that was decreased somewhat but fracture occurred much earlier causing a lower ductility and a lower ultimate tensile strength, attributed to notch sensitivity. Zn7Ag after 12 days and 20 days exposure to ZIF showed some reduction in the yield stress, and also early onset of fracture leading to a large decrease in ductility and some decrease in the ultimate tensile strength, also possibly attributed to notch sensitivity.

An updated binary medium constitutive model of frozen rubber reinforced expansive soil under confining pressure

Rubber reinforcement can effectively improve the swelling characteristics and shear strength of expansive soil. However, rubber-reinforced expansive soil has a more complex structure and mechanical properties, especially in a frozen state, and existing models have not been applied to fully characterize its shear deformation characteristics. In this paper, the updated binary medium model of rubber-reinforced expansive soil is proposed based on the theory of the binary medium model and the homogenization theory of heterogeneous material. The deformation and damage mechanism of frozen rubber-reinforced expansive soil is discussed by using the concept of the binary medium model at the microscopic level, and the updated binary medium model is verified by the triaxial tests of frozen rubber-reinforced expansive soil under confining pressure conditions. The main results obtained: (1) Based on the theoretical framework of rock and soil failure mechanics and the concept of updated binary medium model, saturated frozen rubber-reinforced expansive soil can be abstracted into cementing elements (ice-rubber-soil skeleton) with strong cementation properties, elastic friction elements (rubber) and elastic–plastic friction elements (ice-soil broken skeleton) without cementation properties. (2) The stress–strain curve of frozen rubber-reinforced expansive soil can be divided into three stages: linear elastic stage (ε < 1.33%), elastic–plastic stage (1.33 % < ε < 4.17%) and strain softening stage (ε > 4.17%), which can be interpreted by the conversion between the cementing elements and the friction elements in the updated binary medium model.(3) The measured values of stress and strain of rubber-reinforced expansive soil match the calculated values of the model (R2 = 0.92), and the peak point strain deviation and stress deviation of the model and test values are 9% and 3%, respectively, indicating that the updated binary medium model can better simulate the stress–strain relationship of rubber-reinforced expansive soil. (4) The fitting degrees of the unary medium model and the binary medium model are 0.74 and 0.36, respectively. Compared with the updated binary medium model, there are fewer parameters in the equations, the binary medium model species lacks rubber as an elastic material, and the unary medium model lacks elastoplastic and elastic materials, so it is not suitable for simulating the stress-strain relationship of frozen rubber-reinforced expansive soil.

A Study on the Effect of Doping Metallic Nanoparticles on Fracture Properties of Polylactic Acid Nanofibres via Molecular Dynamics Simulation.

All-atom molecular dynamics simulations are conducted to elucidate the fracture mechanism of polylactic acid nanofibres doped with metallic nanoparticles. Extensional deformation is applied on polymer nanofibres decorated with spherical silver nanoparticles on the surface layer. In the obtained stress-strain curve, the elastic, yield, strain softening and fracture regions are recognized, where mechanical parameters are evaluated by tracking the stress, strain energy and geometrical evolutions. The energy release rate during crack propagation, which is a crucial factor in fracture mechanics, is calculated. The results show that the presence of doping nanoparticles improves the fracture properties of the polymer nanofibre consistently with experimental observation. The nanoparticles bind together polymer chains on the surface layer, which hinders crack initiation and propagation. The effect of the distribution of nanoparticles is studied through different doping decorations. Additionally, a discussion on the variation of internal energy components during uniaxial tensile loading is provided to unravel the deformation mechanism of nanoparticle-doped nanofibres.

Development of a Lytag-silica fume based lightweight concrete and corresponding design equation for pure bending

This study presents a novel Lytag-silica fume concrete (LSFC) for structural and other construction applications. The evaluation of compressive strength development and stress strain relationships of the LSFC light weight was carried out to determine the strength growth in LSFC and for the development of the proposed beam design equation. Four different mix compositions were adopted for concrete grade 20, 30, 40, 50 at cement dosage of 260, 330, 450 and 570 kg/m3 on 24 concrete samples. A rectangular parabolic stress block was derived using representative stress-strain curves, and the results show that the parameter kbal that defines the ultimate design moment in the compressive zone was equal to 0.107 compared to kbal value of 0.167 for a normal weight concrete according to Eurocode 2. The ultimate compressive strain obtained for LSFC was 2.18‰ after 28 days for the LSFC compared to that of the normal weight concrete (NWC) of 3.5‰. The result also shows that 94.15 % of the compressive strength of LSFC was developed within 7 days of age due to the high pozzolanic chemical composition of Lytag and Silica fume. A reduction in embodied carbon was evident on reduction in water to cement ratio. The analysis and design results compared with NWC shows that Lytag-silica fume light weight concrete reduces reinforcement to 47 % with an increase in shear resistance. Scanning Electron microscopy analysis shows that the pathology and microstructure of the lytag-silica fume concrete is characterised with high micro pores with increasing water to cement ratio while the low water to cement ratio exhibit low distribution of pores which is an attribute of good mechanical properties of LSFC. The stress strain behaviour does not display a strain softening phenomena which is indicative of good flexural strength.

Experimental study on the effects of triangular groove inclination angles on the mechanical behavior of sand–concrete interfaces

The mechanical properties of pile–soil interfaces directly affect the bearing capacity of pile foundations. In this study, the effects of triangular groove inclination angles on the mechanical properties of sand–concrete interfaces were investigated. Random rough concrete surfaces were obtained through slurry intrusion testing, and the roughness of concrete surfaces was evaluated based on the sand cone method. According to the roughness of random concrete surfaces, five regular concrete surfaces with different triangular groove inclination angles were constructed. A series of direct shear tests between (i) sand and random concrete surface, (ii) sand and regular concrete surface, as well as (iii) sand and smooth concrete surface were performed. Moreover, a direct shear test of natural sand was conducted. Lastly, a shear strength model considering the triangular groove inclination angle of sand–concrete interfaces was established, and the shear failure mechanism of interfaces was discussed. The results firstly indicated that the shear stress-displacement curves of random rough concrete surfaces were ideal elastic-plastic curves; and the regular rough concrete surfaces were found to incur strain softening under a normal stress of 300 kPa. Secondly, the shear strength of sand–concrete interfaces increased with the increase in groove inclination angle of concrete interfaces. Thirdly, sand was found to achieve the highest shear strength, while sand–smooth concrete interfaces proved to attain the lowest. Lastly, the internal friction angle value of random concrete interfaces was shown to range between the values of concrete surfaces with triangular groove inclination angles of 70° and 90°.

3D FEM Simulation of Titanium Alloy (Ti6Al4V) Machining with Harmonic Endmill Tools

AbstractUsually, end milling operations have been carried out using conventional uniform helix tools with fixed helix angles. Thus, many studies have been conducted to study the effects of these tools on the thermomechanical properties of a milling process. Recently, there have been works that point to the benefits of using harmonic endmills. Harmonic endmills consist of cutting edge profiles that have continuously harmonically varying helix angles. The variation is described using a harmonic function of axial position (elevation) of points on the cutting edge. In this work, a 3D finite element simulation using ABAQUS, is carried out for the complex milling process of Titanium alloy Ti6Al4V. The envelope of the harmonic tool is first generated using a set of MATLAB codes and stored in a Standard Triangle Language (.stl) format. The machine tool is introduced into an FEM program which has been designed to provide for dynamic effects, thermo‐mechanical coupling, material damage law and the criterion for contact associated with the milling process. A Johnson‐Cook material constitutive equation which combines the effects of strain hardening, strain softening, and temperature softening is used. To account for the chip separation criterion, the Johnson Cook damage evolution equation is used. The milling process simulation for Ti6Al4V is then carried out. In the end, the stress distribution and the cutting forces are obtained.