Line Load Research Articles

Exploring the impact of deglaciation on fault slip in the Sangre de Cristo Mountains, Colorado, USA

Few natural examples exist where climate’s influence on tectonics is clear. Based on a study of the Sangre de Cristo Mountains in southern Colorado, we argue that climate-driven changes in ice loads affected spatial and temporal slip patterns on the range-front normal fault. Relict glacial features enable the reconstruction of paleoglacier extents and show variable amounts of footwall ice coverage during the Last Glacial Maximum (LGM). Line load models indicate post-LGM ice melting reduced fault clamping stress by ∼20−55 kPa at seismic depths. Flexural isostatic modeling shows several meters of footwall uplift due to ice unloading with spatial patterns and magnitudes consistent with post-LGM fault throw measured from offset Holocene and late Pleistocene alluvial fans. Post-LGM fault throw rates are at least a factor of five higher than middle and early Pleistocene rates. We infer that climate-modulated ice-load changes can pace fault clamping stress and slip patterns on range-bounding normal faults.

Disparities in dolutegravir utilisation in children, adolescents and young adults (0-24 years) living with HIV. An analysis of the IeDEA Paediatric West African cohort.

We describe the 24-month incidence of Dolutegravir (DTG)-containing antiretroviral treatment (ART) initiation since its introduction in 2019 in West Africa. We included all patients aged 0-24 years on ART from nine clinics in Cote d Ivoire (n=4), Ghana, Nigeria, Mali, Benin, and Burkina Faso. Baseline varied by clinic and was defined as date of first DTG prescription; patients were followed up until database closure/death/loss to follow-up (LTFU, no visit 7 ≥ months), whichever came first. We computed the cumulative incidence function for DTG initiation; associated factors were explored in a shared frailty model, accounting for clinic heterogeneity. Since 2019, 3,350 patients were included; 47.2% were female;78.9% had been on ART ≥ 12 months. Median baseline age was 12.5 years (Interquartile range[IQR]: 8.4-15.8). Median follow-up was 14 months (IQR: 7-22). The overall cumulative incidence of DTG initiation reached 22.7% (95% Confidence Interval (CI): 21.3-24.2) and 56.4% (95% CI: 54.4-58.4) at 12 and 24 months, respectively. In univariate analyses, those aged <5 years and females were overall less likely to switch. Adjusted on ART line and available viral load (VL) at baseline, females >10 years were less likely to initiate DTG compared to males of the same age (adjusted Hazard Ratio [HR] among 10-14 years: 0.62, 95% CI: 0.54-0.72; among ≥ 15 years: 0.43, 95% CI: 0.36-0.50), as were those with detectable VL (> 50 copies/mL) compared to those in viral suppression (aHR: 0.86, 95% CI: 0.77-0.97) and those on protease inhibitors compared to those on non-nucleoside reverse-transcriptase inhibitors (aHR after 12 months of roll-out: 0.75, 95% CI: 0.65-0.86). Paediatric DTG uptake was incomplete and unequitable in West African settings: DTG use was least likely in children <5years, females ≥ 10 years and those with detectable viral load. Maintained monitoring and support of treatment practices is required to better ensure universal and equal uptake.

Influence of Water Ingress at the Shield Tunnel Portal on Tunnel Deformation and Load Capacity Weakening

Abstract. During the construction of shield tunnels, adverse geological conditions can lead to tunnel segment settlement and damage. This study investigates the deformation patterns and changes in load capacity of shield tunnels under water ingress conditions at the portal, using a segment of the Jinan Metro as a case study. Through field measurements and numerical simulations, we analyzed the structural deformation and weakening of load capacity caused by water ingress. The results indicate that significant settlement occurs at both the tunnel crown and invert after water ingress, with a maximum settlement of 181.2 mm compared to the original design axis. The deformation profile of the tunnel primarily resembles a transverse "duck egg" shape, while the segments near the portal exhibit vertical "duck egg" deformations due to grouting and other factors. Multiple cracks and damages were observed in the segments, with up to 16 cracks found in a single ring. Compared to the original design conditions, the bending moment in the tunnel lining increased by approximately 7%, and the axial force increased by about 9%, leading to an 11% reduction in tunnel resistance effects. The findings of this study regarding tunnel lining deformation and load capacity weakening provide valuable insights for similar engineering projects.

Experimental and numerical investigations of double bracket to CHS column joints

The primary objective of this study is to precisely characterize the behavior of double bracket-to-circular Hollow Section (CHS) column joints due to combined internal forces resulting from double tensile loading in opposite directions. In order to accomplish this goal, an experimental program consisting of eight test specimens has been carried out and numerical finite element modeling has been employed for the same specimens to analyze the stresses and deformations that occur within the vicinity of bracket-to-CHS joints. A total of 15 finite element models were constructed to simulate the initial study, addressing boundary conditions and facilitating verification and results comparison. The study included an investigation of various parameters, including the spacing between brackets in the longitudinal direction, as well as the depth-to-thickness ratio of the CHS columns and adding a T-stiffener to the bracket configuration. The study determined that an increase in the diameter-to-thickness ratio of the CHS columns significantly reduced the overall strength of the joint. Furthermore, findings suggested that increasing the longitudinal spacing between brackets resulted in an increase in single-bracket joint strength and a minor reduction regarding joint strength considering the effect of line loading. Moreover, adding a T-stiffener shape for the brackets enhanced the joint strength and prevented bracket tip fracture. In addition, a distinct behavior arises when considering joints with positive eccentricity, where the forces’ line of action extends beyond the circular cross-section of the CHS. In such cases, a reduction in joint strength is observed. Finally, a modification factor “A” is applied to the X-type branch plate-to-CHS strength equation presented by the AISC360-22 to account for the longitudinal spacing between brackets.

Preclinical evaluation of the CD38-targeting engineered toxin body MT-0169 against multiple myeloma.

Despite significant progress in the treatment of multiple myeloma (MM), relapsed/refractory patients urgently require more effective therapies. We here describe the discovery, mechanism of action, and preclinical anti-MM activity of engineered toxin body MT-0169, a next-generation immunotoxin comprising a CD38-specific antibody fragment linked to a de-immunized Shiga-like toxin A subunit (SLTA) payload. We show that specific binding of MT-0169 to CD38 on MM cell lines triggers rapid internalization of SLTA, causing cell death via irreversible ribosome inhibition, protein synthesis blockade, and caspase 3/7 activation. In co-culture experiments, bone marrow mesenchymal stromal cells did not induce drug resistance against MT-0169. In the preclinical setting, MT-0169 effectively lysed primary MM cells from newly diagnosed and heavily pretreated MM patients, including those refractory to daratumumab, with minimal toxicity against nonmalignant hematopoietic cells. MM cell lysis showed a significant correlation with their CD38 expression levels but not with cytogenetic risk, tumor load, or number of prior lines of therapy. Finally, MT-0169 showed efficient in vivo anti-MM activity in various mouse xenograft models, including one in which MM cells are grown in a humanized bone marrow-like niche. These findings support clinical investigation of MT-0169 in relapsed/refractory MM patients, including those refractory to CD38-targeting immunotherapies.

Evaluative assessment of a five-phase and three-phase permanent magnet synchronous machine at varied loads and fault conditions

Multiphase machines are very essential for industrial applications that require high reliability of operation. In this paper, a comparative study of three-phase and five-phase inverter fed permanent magnet synchronous motors (PMSMs) was evaluated with respect to their performance characteristics under a healthy state and during transient disturbances such as varied load and double line to ground faults. To avert inherent high oscillations in speed and torque ripples during fault condition, the machine load was significantly reduced to 1/4th of the full load and a post fault current limiting series dynamic braking resistance (SDBR) with a bypassed switch was introduced to enhance the machine fault tolerant level and improve its operational performance. Spectral analyses were carried out to determine the magnitude of harmonic distortion during these conditions. The simulation results show that the five-phase PMSM achieved a reduced oscillatory transient and a faster settling time of speed and torque under a varied load. It also exhibited good harmonic profiles as indicated in the respective % THD values when compared to the three phase PMSM which is prone to high harmonic overheat. However, when subjected to a double line to ground fault, their various %THD values in speed and torque increased with five-phase PMSM still having a reduced %THD values over the three-phase PMSM. Therefore, for a higher fault tolerant capability, greater efficiency with proven reliability, a five-phase PMSM with a fault current limiting series dynamic braking resistance is a better substitute when compared with the three-phase PMSM in industrial applications where safety and loss minimization is a top priority. All simulation processes in this paper were achieved in MATLAB 2015.

Mitigating power grid impact from proactive data center workload shifts: A coordinated scheduling strategy integrating synergistic traffic - data - power networks

The widespread adoption of cloud computing has markedly escalated the demand for Internet services, rendering Internet Data Centers (IDCs) a critical component in the consideration for demand response (DR) initiatives and grid energy management. This work proposes a flexible scheduling strategy integrating data, traffic, and power networks (DN-TN-PN) to mitigate the impact of proactive IDC workload transfers on power system balance. The spatial-temporal transfer characteristics of EV charging and discharging loads are utilized to track the proactive spatial-temporal transfer of IDC workloads. Considering the influence of weather factors and traffic congestion on EV travel time, an incentive pricing model for EV users is introduced to alleviate bus load fluctuation and line congestion in the distribution network. Numerical simulations demonstrate that the proposed EV pricing strategy, which accounts for the coupled DN-TN-PN, reduces IDC-induced load fluctuations by over 20 % and decreases transmission line occupancy by approximately 15 %, opening up more opportunities for the implementation of DR programs.

Transient stability enhancement of Beles to Bahir Dar transmission line using adaptive neuro-fuzzy-based unified power flow controller

A power system is a complex, nonlinear, and dynamic system, with operating parameters that change over time. Because of the complexity of big load lines and faults, high-voltage transmission power systems are usually vulnerable to transient instability concerns, resulting in power losses and increased voltage variation. This issue has the potential to cause catastrophic events such as cascade failure or widespread blackouts. This problem affects Ethiopia's high-voltage transmission power grid in the northwest area. Because of the increased demand for electrical energy, transmission lines' maximum carrying capacity should be enhanced to maintain a secure and uninterrupted power supply to consumers. To address the problem, ANFIS-based UPFC is used for high-voltage transmission lines. This device was chosen as the ideal alternative due to its capacity to rapidly correct reactive power on high-voltage transmission networks. The PSO algorithm was used to determine the best location for the UPFC. The ANFIS controller receives voltage error and rate of change of voltage error as inputs. Seventy percentage of the retrieved data are used for ANFIS training and 30% for ANFIS testing. To show the performance of the proposed controller, three-phase ground faults are used from a severity perspective. When a three-phase ground fault occurs at the midpoint of the Beles to Bahir Dar transmission line, for instance, the settling time of rotor angle deviation, rotor speed, rotor speed deviation, and output active power of synchronous generators using ANFIS-based UPFC is reduced by 70.58%, 37.75%, 37.75%, and 43.75%, respectively, compared to a system without UPFC. At peak load, PI-based UPFC and ANFIS-based UPFC reduce active power loss by 51.25% and 71.50%, respectively, compared to a system without UPFC on the Beles to Bahir Dar transmission line. In terms of percentage overshoot and settling time, ANFIS-based UPFC outperforms PI-based UPFC for transient stability enhancement.

Two-Stage Optimization Model Based on Neo4j-Dueling Deep Q Network

To alleviate the power flow congestion in active distribution networks (ADNs), this paper proposes a two-stage load transfer optimization model based on Neo4j-Dueling DQN. First, the Neo4j graph model was established as the training environment for Dueling DQN. Meanwhile, the power supply paths from the congestion point to the power source point were obtained using the Cypher language built into Neo4j, forming a load transfer space that served as the action space. Secondly, based on various constraints in the load transfer process, a reward and penalty function was formulated to establish the Dueling DQN training model. Finally, according to the ε−greedy action selection strategy, actions were selected from the action space and interacted with the Neo4j environment, resulting in the optimal load transfer operation sequence. In this paper, Python was used as the programming language, TensorFlow open-source software library was used to form a deep reinforcement network, and Py2neo toolkit was used to complete the linkage between the python platform and Neo4j. We conducted experiments on a real 79-node system, using three power flow congestion scenarios for validation. Under the three power flow congestion scenarios, the time required to obtain the results was 2.87 s, 4.37 s and 3.45 s, respectively. For scenario 1 before and after load transfer, the line loss, voltage deviation and line load rate were reduced by about 56.0%, 76.0% and 55.7%, respectively. For scenario 2 before and after load transfer, the line loss, voltage deviation and line load rate were reduced by 41.7%, 72.9% and 56.7%, respectively. For scenario 3 before and after load transfer, the line loss, voltage deviation and line load rate were reduced by 13.6%, 47.1% and 37.7%, respectively. The experimental results show that the trained model can quickly and accurately derive the optimal load transfer operation sequence under different power flow congestion conditions, thereby validating the effectiveness of the proposed model.

Reliability and line loading enhancement of distribution systems using optimal integration of renewable energy and compressed air energy storages simultaneously under uncertainty

Recently, with the significant growth of load demand, further interest in renewable energy sources (RESs) incorporated into electric distribution systems (DSs) has become important. However, the output powers' stochastic fluctuations of the photovoltaic (PV) and wind turbine (WT) generation sources, as well as the load demand, result in obvious operational challenges related to the reliability and line loading of these systems. Therefore, this present study is intended to enhance the load-oriented reliability indices (LORIs), the customer-oriented reliability indices (CORIs), and the line loading index (LLI) of the DSs by assigning the optimal integration of RESs and compressed air energy storages (CAESs) through the determination of both the optimal placement and capacities of RESs and CAESs simultaneously, as well as the optimal charging and discharging powers of the CAESs and their initial state of charge based on the red-tailed hawk (RTH) optimization technique. The Monte Carlo Simulation (MCS) and the Scenario-based Reduction (SBR) uncertainty methods are implemented to address the uncertainties of RESs and loading. The influences of the linear failure rate of DS's feeders and the installation of protective devices are also demonstrated. The efficiency of the intended methodology is demonstrated on the IEEE 69-bus and IEEE 33-bus DSs associated with voltage-dependent, time-varying mixed loads. The outcomes obtained from the suggested RTH are compared to those of other reported optimization techniques to validate its effectiveness. The results reveal that the optimal integration of RESs along with CAESs in the IEEE 69-bus test DS can improve the energy not supplied (ENS), system average interruption duration index (SAIDI), system average interruption frequency index (SAIFI), average service unavailability index (ASUI), and LLI by 1.09 %, 1.86 %, 1.73 %, 1.89 %, and 64.53 %, respectively.

Modeling the deformation of thin-walled circular tubes filled with metallic foam under two lateral loading patterns

Thin-walled circular tubes with metallic foam fillers are widely used in various engineering fields. This work examines the plastic behavior of thin-walled circular tubes filled with metallic foam under two different lateral loading patterns, by using both analytical and numerical methods. Two types of loading indenters, including a line load and a rigid plane, are considered. There have been very few studies on the lateral compression of foam-filled circular tubes crushed by a line load or a rigid plane. The analytical models assume that the tubular wall material is rigid and ideally plastic, and that the metallic foam fillers maintain a constant resistance known as plateau stress. Using the principle of virtual velocities, we derive succinct explicit solutions for the crushing forces as well as deformation characteristics in regard with the radius of the tubes, the flow stress of the tubular wall and the plateau stress of the filled foam under the two loading conditions. Finite element analysis is performed using the ABAQUS2023/Explicit code to model aluminum alloy circular tubes filled with aluminum foam. A comparison and analysis of the deformation characteristics of the tubular top generator and foam cross-sections are conducted. The proposed analytical crushing forces and deformation properties obtained herein agree well with the numerical simulation results and outperform previous theoretical models, which may serve as valuable formulations for the engineering application.

Volcano tsunamis and their effects on moored vessel safety: the 2022 Tonga event

Abstract. The explosion of the Hunga Tonga–Hunga Ha'apai volcano on 15 January 2022 (Tonga 2022) was the origin of a volcano-meteorological tsunami (VMT) recorded worldwide. At a distance exceeding 10 000 km from the volcano and 15 h after its eruption, the moorings of a ship in the port of La Pampilla, Callao (Peru), failed, releasing over 11 000 barrels of crude oil. This study delves into the profound implications of the Tonga 2022 event, investigating whether it could have led to the breaking of the mooring system. We conducted a comprehensive analysis of this significant event, examining the frequency content of the time series recorded at tide gauges, DART (Deep-ocean Assessment and Reporting of Tsunamis) buoys, and barometers in the southern Pacific Ocean. Our findings revealed that the maximum energy of the spectra corresponds to the 120 min wave period off the coast of Peru, with the arrival time of these waves coinciding with the time of the accident in the port. We used a Boussinesq model to simulate the propagation of the volcano-meteorological tsunami from the source to the port in Peru to study the impact of those waves on the mooring system. We used the synthetic tsunami recorded in the port as input for the model that simulates mooring line loads based on the ship's degrees of freedom. The results suggest that the 120 min wave triggered by the VMT could significantly increase mooring stresses due to the resulting hydrodynamic effects, exceeding the minimum breaking load (MBL). We conclude that the propagation of the long wave period generated by the VMT caused overstresses in moored lines that triggered accidents in port environments. This event showed the need to prepare tsunami early warning systems and port authorities for detecting and managing VMTs induced by atmospheric acoustic waves. The work provides new insights into the far-reaching impacts of the Tonga 2022 tsunami.

Fast-response and high figure of merit phase shifter based on polymer- stabilised liquid crystals

ABSTRACT This article presents a novel fast-response and high figure of merit (FoM) phase shifter based on polymer-stabilised liquid crystal (LC) for Ka-band. The developed LC phase shifter (LCPS), utilising a coplanar differential line loading 19 parallel-plate variable capacitors with 4.6 μm LC-cell, adopts polymer-stabilised LC technology in which the parallelly orientated polymer networks facilitate the LC molecules’ return to their initial state upon removal of the bias voltage, thus accelerating response time. The proposed LCPS has been fabricated to evaluate its superior capabilities. The experimental results closely match the simulation results, confirming its good congruity. This design has measured S 11 < −10 dB in 29–31 GHz. LCs with different HCM002 concentrations are injected to LCPS, and the experimental outcomes showed that LCs with 9 wt% HCM002 concentration significantly improve the response time of LCPS to 2.8 ms with a high FoM of 91.2°/dB at 30 GHz.

Stress field measurements using quantitative schlieren

Quantitative schlieren analysis is extended here to optically transparent solids in quasi-static and dynamic experiments to measure stress distributions. The quasi-static experiments in polymethyl methacrylate (PMMA) compared refraction angles and stress gradients calculated from schlieren images to the analytical Flamant solution of a line load on a half-space. The quantitative schlieren measurements of the stress field in the thin sample with a load compared well to the analytical solution. The analysis method was then extended to explosive induced shock waves in PMMA. The explosive induced response of PMMA was experimentally studied using high-speed schlieren to visualize the shock propagation in conjunction with Photon Doppler Velocimetry (PDV) to record surface velocity histories. The stress state estimated from the schlieren images was compared to the stress calculated from the PDV measurements. High-speed imaging limitations caused the shock wave to not be fully resolved in the images, but was resolved in the PDV measurement. The stress state behind the shock calculated from the high-speed images followed a similar trend to the stress calculated from the PDV measurements.

An Adaptive Droop Control for Power Sharing Between Three Phase Parallel Inverter in Autonomous Microgrid

The development of an adaptive droop controller is for power sharing between three-phase parallel inverters. Traditionally, droop controllers have been employed in conventional power systems to allocate the load among generators with varying capacities. Our approach involves the utilization of an adaptive control technique. This method is designed for a setup involving three-phase parallel inverters linked to an AC microgrid, to enhance the proportional distribution of active power despite changes in feeder network characteristics and loads. The proposed control mechanism automatically tunes the frequency droop parameter to address mismatch frequencies. The system includes two sets of three-phase inverters regulated by a combination of P-F droop control, an enhanced droop control loop, and PI controllers. The adaptive droop coefficient control is capable of addressing problems where power distribution inaccuracies arise due to different line loads as well as different inverter capacities.

Injury to the palmar supporting structures of the fetlock alters limb stiffness and fetlock angle.

In vivo measurement of limb stiffness and conformation provides a non-invasive proxy assessment of superficial digital flexor tendon (SDFT) and suspensory ligament (SL) function. Here, we compared it in fore and hindlimbs and after injury. To compare the limb stiffness and conformation in forelimbs and hindlimbs, changes with age, and following injury to the SDFT and SL. Retrospective cohort study. Limb stiffness was calculated using floor scales and an electrogoniometer taped to the dorsal fetlock. The fetlock angle and weight were simultaneously recorded five times with the limb weight-bearing and when the opposite limb was picked up (increased load). Limb stiffness of both limbs was calculated from the gradient of the regression line of angle versus load. Fetlock angle when the weight was zero was extrapolated from the graph and used as a measure of conformation. Limb stiffness was measured in uninjured forelimbs (n = 42 limbs), hindlimbs (n = 19 limbs), forelimbs with SDFT injury (n = 18) and hindlimbs with SL injury (n = 5). Limb stiffness correlated with weight in forelimbs as shown previously (p < 0.001) but also in hindlimbs (p = 0.006). When normalised to the horse's weight (503 kg, IQR 471.5-560), forelimb stiffness was significantly higher (22.3 [±4.5] × 10-3 degree-1) than for the hindlimb (16.4 [±4.0] × 10-3 degree-1; p < 0.001). While there were no significant differences between forelimb and hindlimb conformation in unaffected or SDFT injury, both limb stiffness and conformation was significantly greater in limbs with SL injury (p = 0.009 and p = 0.002, respectively). Small sample size, lack of clinical data including lameness and quantification of injuries. Injury to the forelimb SDFT does not alter limb stiffness or conformation in the long-term, while hindlimb SL injury simultaneously increases limb stiffness and fetlock angle, suggesting an increase in SL length following injury.

TRACE assessment of density wave instability onset with void reactivity feedback under natural circulation

Density wave oscillation (DWO) is an important safety concern for boiling water reactors (BWR) due to their high void fraction in the core. Power extensions to existing reactors such as the Maximum Extended Load Line Limit Analysis Plus (MELLLA+) lead to increase susceptibility of DWO-type instability following an anticipated transient without scram (ATWS). Experiments performed at the Karlstein Thermal Hydraulic Test Facility (KATHY) have reproduced the reactivity feedback mechanism in BWRs under ATWS conditions. Using a neutronics module simulator, the KATHY facility was able to provide data on the effect of different neutronic parameters on DWO onset. This paper serves to assess the capability of the thermal-hydraulics code TRACE V5P7 for simulating DWO onset and development under natural circulation with neutronic feedback. A model of the KATHY natural circulation facility is created in TRACE and a reactivity feedback mechanism is implemented using a manual control scheme to simulate the parametric effects provided by the tests. This comparison allows for an assessment of the TRACE code as well as a better understanding of the instability mechanisms and behavior under the given conditions.

BEOL-Compatible MFMIS Ferroelectric/ Anti-ferroelectric FETs—Part II: Mechanism With Load Line Analysis and Scaling Strategy

BEOL-Compatible MFMIS Ferroelectric/ Anti-ferroelectric FETs—Part II: Mechanism With Load Line Analysis and Scaling Strategy

Bond performance of fly ash-based geopolymer mortar in simulated concrete sewer substrate

Geopolymers have been extensively explored as a promising repair material for deteriorated Ordinary Portland Cement (OPC) concrete elements. However, knowledge of the adhesion performance of geopolymer to concrete substrates is limited. This study investigates the bond performance of low calcium fly ash geopolymer (FAGP) mortar and concrete for holistic acidic environmental conditions, such as in sewer rehabilitation. The bond evaluation was conducted by slant-shear test, performed at different substrate conditions, namely Rough-Dry, Rough-Saturated, Smooth-Dry and Smooth-Saturated, to simulate the in-service condition of a typical sewer pipe wall. The standard OPC repair mortar and a commercially available proprietary geopolymer repair product (P-GP) were evaluated and compared as controls to ascertain the viability of geopolymer for repair application. The shear bond strength of FAGP mortar was found to be in the order of 14 MPa, outperforming OPC and P-GP in all substrate conditions. Even though FAGP bond strength was insensitive to roughened substrate moisture levels, the synergistic effect of smoothness and moisture condition appeared detrimental. The testing of the prototype geopolymer-coated concrete pipe under line loading showed no sign of delamination at the bond plane. OPC and P-GP exhibited a distinct bond separation, which commenced at only 20 % of the ultimate load. The acid resistance and low permeability of FAGP mortar appeared to aid in preserving the repair bond.

On comparison of fracture energy measured for six hot mix asphalt composite mixtures using force–load line displacement and force–crack mouth opening displacement curves at intermediate temperatures and different loading rates

AbstractThere are two methods for determining the fracture energy (Gf) of hot mix asphalt (HMA) composites at intermediate temperatures: (i) load–crack mouth opening displacement (CMOD) and (ii) load–load line displacement (LLD) curves. The effects of these two methods on the Gf values of different HMA mixtures are investigated at different loading rates and temperatures. A large number of semicircular bend (SCB) specimens were tested under mode I at different temperatures of 5°C, 15°C, and 25°C and loading rates of 1, 5, 10, and 50 mm/min. The three‐dimensional (3D) fracture energy surface plots obtained from the tests revealed that both temperature and loading rate have noticeable effects on the fracture energy, such that Gf values generally increased by increasing the loading rate and reducing the temperature. Also, the Gf values measured by the LLD method were higher than those by the CMOD method for lower temperatures and lower loading rates (i.e., below 10 mm/min). For the higher loading rates, the Gf values determined by the CMOD method were higher than those by the LLD method. Furthermore, the HMA type had meaningful influences on the variations of Gf at different temperatures and loading rates.